10 Free and useful computer-aided design software

computer-aided design (CAD) is a combination of computer programs and systems that allow engineers and architects to design detailed two- or three-dimensional models of physical objects, such as mechanical parts, buildings, and molecules.

It specially used to design curves and figures in two-dimensional (“2D”) space; or curves, surfaces, and solids in three-dimensional (“3D”) objects. There are so many “free” CAD programs out there but only a handful are either really free or useful. Here is 10 Free and useful computer-aided design software.

1. Archimedes

   
   Archimedes is an open source Computer aided design (CAD) software that mainly focus on architectural design. It is a robust system built over Eclipse’s Rich Client Platform fully based on plug ins. This means it is easily extensible but also has a pretty thin core that allows you to select the features you need and drop the other ones easily.
   Features :
   1. Basic drawing tools like; Lines, Polylines, Arcs,Circles,Editable Text,Explode and Offset.
   2. Advanced CAD functions like; Trimming, Filleting and Area measurement.
   3. Hand drawing easily exported in scalable vector graphics (SVG) format
   4. Auto save functionality
   5. English, Portuguese, and Italian language support
   Website: Archimedes

2. BRL-CAD

   
   BRL-CAD is an open source cross-platform CAD system based on constructive solid geometry (csg) modeling system that includes interactive 3D solid geometry editing, high-performance ray-tracing for rendering and geometric analysis, image and signal-processing tools, network-distributed frame buffer support, a system performance analysis benchmark suite, libraries for robust geometric representation and analysis library, path-tracing and photon mapping support for realistic image synthesis and embedded scripting interface.
   Website: BRL-CAD

3. Free CAD

   
   freeCAD is a open source Multi-platform 3D CAD modeler with advanced Motion Simulation capabilities. It is suitable for anyone interested in learning 3D CAD and Motion Simulation for free before using more sophisticated packages. It mainly focus on mechanical engineering and product design but also fits in a wider range of uses around engineering, such as architecture or other engineering specialties. The program runs on Windows, Linux PC, Macintosh PPC and other Unix’s. Assembly data are unchanged across platforms.
   Website : FreeCAD – open source 3D CAD system

4. HeeksCAD

   
   HeeksCAD is a free, open source CAD application written by Dan Heeks. it specially designed to give you some useful features such as Import solid models from STEP and IGES files. Draw construction geometry and lines and arcs. Create new primitive solids, or make solids by extruding a sketch or by making a lofted solid between sketches. Modify solids using blending, or boolean operations. Save IGES, STEP and STL. Printer plot the 2D geometry or to HPGL. Import and export dxf files; lines, arcs, ellipses, splines and polylines are supported. Use the geometric constraints solver to create accurate drawings from rough sketches.
   Website : HeeksCAD – open source CAD applications

5. monoworks

   
   MonoWorks is a full-featured, Open Source 3D Computer Aided Design (CAD) suite of Computer-Aided Drafting, Design, and Engineering tools that includes object-oriented math and modeling libraries, as well as interactive viewing and modeling applications. From simple tasks to advanced automation and visualization, the MonoWorks Project aims to provide a powerful and flexible set of engineering tools.
   Website: Monoworks – Open Source 3D CAD suite

6. MeshLab

   
   MeshLab is an open source, portable, and extensible system for the processing and editing of unstructured 3D triangular meshes. MeshLab is aimed to help the processing of the typical not-so-small unstructured models arising in 3D scanning, providing a set of tools for editing, cleaning, healing, inspecting, rendering and converting this kind of meshes.
   Features :
   1. Interactive selection and deletion of portion of the mesh. Even for large models.
   2. Painting interface for selecting, smoothing and coloring meshes.
   3. Easy to Input/output in many formats:
      • import:PLY, STL, OFF, OBJ, 3DS, COLLADA, PTX, V3D, PTS, APTS, XYZ, GTS, TRI, ASC, X3D, X3DV, VRML, ALN file formats
      • export:PLY, STL, OFF, OBJ, 3DS, COLLADA, VRML, DXF, GTS, U3D, IDTF, X3D file formats
   4. Mesh Cleaning Filters
   5. Remeshing filters
   6. Various Colorization/Inspection filters
   7. Interactive Mesh Painting
   8. Measuring tool. You can take linear measures between points of the displayed meshes
   9. Slicing tool. A new tool that allows to export planar sections of a mesh in SVG format
   10. 3D Scanning tools
   11. OpenGL Shader based rendering
   12. Large rendering (up to 16k x 16k) for high quality printing
   13. The history of the all performed cleaning/editing actions can be re-played on different meshes or saved and for archival purposes.
   14. Extendible plugins based architecture
   Website: MeshLab – 3D mesh processing system

7. Misfit Model 3D

   
   Misfit Model 3D is an OpenGL-based 3D model editor that works with triangle-based models. It supports multi-level undo,skeletal animations, texturing mapping, scripting, command-line batch processing and a plugin system for adding new features. It is specially designed to be easy to use and easy to extend with plugins and scripts.
   Website: Misfit Model 3D – 3D model editor

8. Open CASCADE

   
   Open CASCADE is a powerful CAD/CAM/CAE kernel and development platform for 3D modeling applications. It consists of reusable C++ object libraries and a set of development tools that are available in Open Source.
   Website: Open CASCADE

9. QCAD – 2D CAD system

   
   QCAD is a Multi-platform CAD software Suite specially designed for 2D design and drafting. it’s a powerful yet easy to use 2D CAD program for Linux, Windows, and Mac OS X and uses the AutoCAD DXF file format internally as its standard file format. While other CAD packages are often rather complicated to use, QCad tries to stay comfortable, and even an absolute beginner can create professional drawings with a minimum of effort.
   Website: QCAD – multi-platform 2D CAD system

10. SALOME Open source CAD

    
    Salome is an open source Integration Platform for Numerical Simulation that provides a generic platform for Pre- and Post-Processing for numerical simulation. It is based on an open and flexible architecture made of reusable components. the software is a cross-platform solution and distributed as open-source software under the terms of the GNU LGPL license.
    It use as standalone application for generation of CAD models, their preparation for numerical calculations and post-processing of the calculation results.
    Features:
    1. Easy to Create/modify, import/export (IGES, STEP, BREP), repair/clean CAD models
    2. Supports interoperability between CAD modeling and computation software (CAD-CAE link).
    3. Mesh CAD models, edit mesh, check mesh quality, import/export mesh (MED, UNV, DAT, STL)
    4. Makes easier the integration of new components into heterogeneous systems for numerical computation.
    5. Easy to Handle physical properties and quantities attached to geometrical items
    6. Display computation results (scalar, vectorial)
    7. Provides a generic user-friendly and efficient user interface, which helps to reduce the costs and delays of carrying out the studies.
    8. Reduces training time to the specific time for learning the software solution based on this platform
    9. Manage studies (create, save, reload)
    10. Provides access to all functionalities via the integrated Python console.
    Website: SALOME open source CAD

40+ Free Hacking Tutorials

  Here are some great hacking tutorials and resources that you can explore in your journey to learn hacking:

1. Hacking Tutorials for Beginners By BreakTheSecurity.com

Unless you know how to hack, you cannot defend yourself from hackers. Break The Security(BTS) provides Penetration Testing and Ethical Hacking tutorials. It guides users to get into the PenTesting and Ethical Hacking World.

2. How to learn Ethical hacking By Astalavista.com

You can learn all there is to know about Ethical hacking over here.

3. Penetration Testing Tutorial By Guru99.com

Here you learn Penetration Testing by practice. The goal of this testing is to find all security vulnerabilities that are present in the system being tested. This tutorial takes boredom out of learning and makes education a fun experience.

4. Backtrack Penetration Testing Tutorial

This Backtrack Penetration Testing Tutorial is a penetration testing tutorial using Backtrack Linux. Backtrack is the best penetration testing distribution. Offers some penetration testing programs and these programs will used in this Backtrack Penetration Testing Tutorial.

5. Introduction to Penetration Testing

The difference between penetration testing and hacking is whether you have the system owner’s permission. This tutorial helps you understand this better.

6. Information Gathering with Nmap

This tutorial consists of a series that will give a basic walkthrough of a penetration test. However, many tools on the backtrack distro will not be covered in these and could be asked from the author separately.

7. Simple How To Articles By Open Web Application Security

Series of articles describing how to perform a specific activity that contributes to application security.

8. The Six Dumbest Ideas in Computer Security

Introduces you to the six dumbest ideas in computer security: the anti-good ideas that come from misguided attempts to do the impossible.

9. Secure Design Principles

While there are many specific security practices, they flow from a small set of well-accepted principles. Understanding the fundamental principles puts you in the best position to implement specific practices where needed in your own projects. This tutorial guides you through the same.

10. 10 steps to secure software

The author and security analyst recommends that programmers follow some principles for developing secure software that is today's weakest link.

11. Introduction to Public Key Cryptography

Public-key cryptography and related standards and techniques underlie security features of many Red Hat products, including signed and encrypted email, form signing, object signing, single sign-on, and the Secure Sockets Layer (SSL) protocol. This document introduces the basic concepts of public-key cryptography.

12. Crypto Tutorial

The page contains many crypto tutorials, totalling 973 slides in 12 parts, of which the first 10 (+ part 0) are the tutorial itself and the 12th is extra material which covers crypto politics.

13. Introduction to Cryptography

Deals with the very basics of cryptography.

14. An Overview of Cryptography

There are many aspects to security and many applications, ranging from secure commerce and payments to private communications and protecting passwords. One essential aspect for secure communications is that of cryptography, which is the focus of this chapter.

15. Cryptography Tutorials Herong's Tutorial Examples

Collection of notes and sample codes written by the author while he was learning cryptography technologies himself. Topics include blowfish, certificate, cipher, decryption, DES, digest, encryption, keytool, MD5, OpenSSL, PEM, PKCS#8, PKCS#12, private key, public key, RSA, secret key, SHA1, SSL, X.509.

16. The Crypto Tutorial Herong's Tutorial Examples

Easy-to-use, interactive cryptography tutorial. You have the opportunity to learn the secrets of cryptography in 30 lessons without having any background knowledge.

17. Handbook of Applied Cryptography 

This ebook contains some free chapter from one of the popular cryptography books.

18. Network Penetration testing Guide

Risk assessment is a critical first-step in the information security lifecycle. Network penetration testing offers an invaluable way to establish a baseline assessment of security as it appears from outside the organisation's network boundaries.

19. How to hack anything in Java

Many applications in the enterprise world feature thick Java clients. Testing the security of such applications is considered practically more difficult than a similar browser-based client because inspecting, intercepting and altering application data is easy in the browser.

20. Mcafee on iPhone and iPad Security

Mobile application penetration testing is an up and coming security testing need that has recently obtained more attention, with the introduction of the Android, iPhone, and iPad platforms among others.

21. A Good Collection of White papers on security and vulnerabilities

Collection of white papers from different sources and some of these white papers are really worth referring.

22. Engineering Principles for Information Technology Security

The purpose of the Engineering Principles for Information Technology (IT) Security (EP-ITS) is to present a list of system-level security principles to be considered in the design, development, and operation of an information system.

23. Basic Principles Of Information Protection

As computers become better understood and more economical, every day brings new applications. Many of these new applications involve both storing information and simultaneous use by several individuals. The key concern in this paper is multiple use. For those applications in which all users should not have identical authority, some scheme is needed to ensure that the computer system implements the desired authority structure.

24. Open Web Application Security Project

Application security principles are collections of desirable application properties, behaviors, designs and implementation practices that attempt to reduce the likelihood of threat realisation and impact should that threat be realised.

25. Cryptography Course

Learn about the inner workings of cryptographic primitives and how to apply this knowledge in real-world applications!

Websites

26. http://www.astalavista.com/

27. http://packetstormsecurity.com/

28. http://www.blackhat.com/

29. http://www.metasploit.com/

30. http://sectools.org/

31. http://www.2600.com/

32. DEF CON - Hacking conference

33. http://www.breakthesecurity.com/

34. http://www.hacking-tutorial.com/

35. http://www.evilzone.org/

36. http://hackaday.com/

37. http://www.hitb.org/

38. http://www.hackthissite.org/

39. http://pentestmag.com

40. http://www.securitytube.net/

10 Must-Have Free Softwares in your Pc

1. CCleaner: 

To maintain a good system, its clean-up facilities should always be up to the mark. One of the most excellent tools to serve this purpose is CCleaner which deletes unwanted files, browsing history, cookies and cache files.



2. CutePDFWriter: 

This is a PDF converter which is used for professional reasons mostly. PDFs can be created through this software quite easily and this converter has some other functions too like making PDF booklets, combining PDF files etc. The software is very fast to use and it can be used on Linux, Mac OS, Windows and Solaris too.



3. CCEnhancer: 

Cleaning up your computer becomes much more interesting with CCEnhancer. It is actually a boost to the previous one, CCleaner.



4. TeamViewer: 


TeamViewer is a free software which allows connecting to any PC or server, anywhere in the world. This software allows remote control of the partner PC too.



5. IrfanView: 

IrfanView is one of the best free media tools for PC which acts as a graphics viewer and image editor. It converts files, crop images, add special effects and perform all the basic editing tasks.



6. Picasa: 

Picasa is a free product from Google which acts as an image viewer and editor. It is also a famous photo sharing website. Picasa is mainly used in case of digital photos.



7. Dropbox: 

This is the best back-up program for your computer, which ensures all your data is safe. This software is free and this cloud drive lets you share all your documents easily.



8. ClipX: 

ClipX is a clipboard enhancer which works as a clipboard history manager. It also stores graphics, texts and it also supports plug-ins.



9. FileZilla: 

Users who are into a job of uploading and downloading files to and from a server, FileZilla is the best free FTP utility for them. It shares files without any hassle, provided there is no internet breakage in between the file sharing time.



10. Avira AntiVirus: 

Avira AntiVirus, a free protection against viruses, provides security from all kind of online threats, and it protects your privacy throughout. With Avira your data is secure as it has been highly successful in detecting malware.

 

Build A Web or Mobile App Quickly

1. Alpha Anywhere

This tool can be used to build apps for building web-based applications, mobile appliacations for Android, Windows Phone and iOS and for S

2. App Press

This tool is suited for iPhone, iPad and Android developers who are looking for a no code, web based application.

3. AppArchitect

Use this one when you're developing for Apple's iPhone or iPad devices.

4. Form.com

This is a web-based form builder that is well suited for enterprises.

5. iBuildApp

Templates for building apps are important. This tool provides Android and iOS (iPhone and iPad) applications.

6. QuickBase

This platform for mobile web database and web application development has over 300 templates to offer.

7. Salesforce1

This is an useful tool for quickly building HTML5, Android and iOS applications and web applications.

8. ViziApps

This tool is a combination of visual designer and customisable sample apps along with code generation for mobile web, iOS and Android.

9. Mobile Chrome Development Kit

This is an Apache Cordova-based developer preview tool that targets iOS, Android and Chrome apps.

10. Appcelerator

This is an enterprise level mobile development tool that brings an IDE, SDK and back end cloud services to you. 

Great Alternatives to TALLY (Open Source)

1. Post Books: 

This is an open source accounting as well as resource planning software. It's designed to be used in all the medium and small sized enterprises. This is a free software which was released under the CPAL license. Post Books accounting software was initially written in English language but now it has become multi-lingual including Spanish, Russian, Chinese, Turkish, Portuguese as well as French among others.

Post Books software is divided into modules like Sales, Accounting, CRM, Manufacturing, Products, Inventory and Purchase. The modules are arranged in an interactive manner depending on the requirements of the clients. Besides that, this software also supports multi- currency and multi- lingual capability. Post Books is an international software which can be used for a variety of business accounting purposes worldwide.

2. BS1 Accounting: 

BS1 Accounting is open source inventory software which is basically useful for business enterprises. This software takes care of functions like Accounts payable, Accounts receivable, Inventory, Sales and General ledger. This software fits the size of your screen effectively and with its user- friendly interface, it is used by a large number of people.

This software helps in easy export and import of goods due to its multi- currency feature. It is also capable of tracking the receivables and payables of various currencies distinctly.

3. TAMS: 

TAMS or Time Accounting Management Software is a unique accounting software, based on PHP/ PostgreSQL. This software offers a whole new range of functionalities in its package including billing, accounting as well as tracking packages. The TAMS software is mainly useful for small businesses and also the companies involved in consulting work. It allows generating bills, saving lot of time.

Important projects don't miss their deadlines and this software provides guidance so that the finance does not exceed from the planned budgets.

4. Turquaz Financial Accounting: 

This is a user-friendly accounting software which is suitable for small and medium sized enterprises. It is double entry financial software which aims at performing target operations like accounts payable, management of inventory, accounts receivable, general ledger, advanced report, journal and advanced analysis. This software is compatible with multiple currencies and multiple languages.

This software becomes a useful tool as it includes a variety of functionalities, while offering a user- friendly approach to the users.

5. GNU Cash: 

GNU Cash is a small but efficient software to handle your accounts, especially the financial matters related to your enterprise. This software is freely licensed under GNU. It's also compatible with other operating systems like Linux, Solaris, BSD, Microsoft Windows as well as Mac OS X. GNU Cash is very easy to use and it allows you to track your bank accounts, your expenses and incomes.

The architecture of this software is based in professional principles of accounting.

6. Turbo Cash: 

Turbo Cash is an entry level inventory control software which is designed to be used by single users. It is mostly used by comparatively small networks as well as other distributed networks. It is also compatible with other operating systems like Linux in Wine and Delphi developments in Windows. It supports developer’s script too.

Its other specifications include multi- language and multi- currency features. There is also a local Plug In which is included to make the experience more worthy for the users. This software is most ideal for SMEs.

7. OBA: 

OBA or Open Business Accounting is a useful web- based accounting software and it has been modified from SQL ledger in order to suit auditors, accountants and people who are involved in similar kinds of jobs. Some very useful and easy to use modules are included in this software like sales summary, quick data entry as well as unique transaction number. It is also capable of performing functions like accepting payments, delivering sales and keeping track of all your transactions.

Courtesy: Dreamcss 

Skills That Make You A Real Geek

   

1. Know Your Hardware

When it comes to hardware, you should be able to tell what's what, even the oldest and most obsolete chips make no difference to a nerd. In fact, we specialise in those. Well, that and finding the most out of date hardware from old equipment and putting them to good use in new ones.

2. Run All Your Essential Apps on a USB Stick

It is possible to install various apps on a thumb drive, but if you're a nerd, you would already know that. The rite of passage is in carrying around a thumb drive with all your apps in it, so you can access them and their settings from any computer.

3. Straighten the Pins on an Older CPU

When the pins of an old CPU or card have been bent, you probably throw it away. Not if you're a nerd. There are two simple tricks to realign these pins. The first is to run a credit card up and down through the rows of pins and the second is to take a mechanical pencil and realign them by sheating them in the pencil's tip. The first method works when the pins are lightly bent, while the second one works when the credit card trick fails.

4. Know the 13 Basic HTML Tags

to

-- Heading styles

-- New paragraph


or
-- Single line break

-- Hidden comment

---

-- Horizontal rule line

-- Bold text

-- Emphasise text

-- Strong emphasis

-- Italicise

-- Underline

  -- Non-Breaking space

-- Anchor a link

 -- Insert image

5. Get Through to Executive Customer Service

Nerds always get through to the executive customer service, somehow they always do. An average person doesn't know that there are ways to get around robotic customer service menus  (Gethuman.com). Moreover, when nothing works, they find and call the number to a company's corporate offices.

6. Beat Quake in Under an Hour

The art of speed runs is almost non-existent nowadays. Remember how people used to finish Quake in 15 minutes or less? That's a skill that makes you an alpha nerd.

7. Build a Hackintosh

You may not buy a Mac PC yourself, but you've tried out Apple's OS X platform, just to see if it lives up to the hype. Moreover, you may even have tried to build yourself your own custom assembled PC, which runs the OS X platform. In other word, built yourself a Hackintosh.

8. Watch TV Shows on the Internet (Legally!)

There are a number of websites out there, led by Hulu, which offer video streaming services, allowing you to watch popular shows online. A nerd would watch his or her shows online through these legal websites rather than committing piracy.

9. Get Around the Content Filter on Public Computers

Content restrictions on public computers never go well with you. You would much rather get around these restrictions and continue on with things that you want to do on the computer. The first option is to use a proxy website, but if that doesn't work, then you handy portable thumb drive comes into use. You would have a portable version of Firefox enabled with Tor installed in the thumb drive. Use that.

10. Recite pi to 23 Decimal Places

Here's what the value is. Memorise it.

3.141592653589793238462643

11. Replace the Controller Board on a Hard Drive

When hard drives go bust, replacing their Controller Board is often the way to fix them. In nerd land, this an essential skill, which keeps your data safe.

12. Benchmark Your Computer

Nerds are always working to improve hte performance of their PCs. But doing this is of no use or fun if one can not know how much the performance has improved. This is where Benchmarking software comes in.

13. Decorate Your Room Using Only Printer Paper

You know you can create your poster right? As long as you have a reasonably high resolution image, the website Rasterbator can turn it into a poster and you can print it out

14. Securely Erase Your Data So it Can't be Recovered

You erase your data securely, so that it can not be recovered. Face it, even though you know that it might get you into trouble, you have done it. You will go on a manufacturer's website and download the 'zero fill' software for your hard drive. Then you will delete whatever files you need to.

15. Get into a Windows Computer if you Forgot Your Password

Lost your Windows login password for your PC? Doesn't matter, you know there are ways to recover it. You can use a cracker, that is a software that cracks this password. In addition, you can also do some other things, like checking whether an admin account is present.