Before reading the list we are requesting you to please comment all the sites that you think should be there and we will modify the list. This will make this post a good place to find any website.
Online Contest :
Online datastructures and algorithms:
Learn Web Development:
Web designing templates:
- Coding Ground by tutorials point
- Online Compiler
- GDB Online Debugger for debugging your c/c++ programs online.
This is a small list that I think computer guys should know. This is very small list. I will extend the list give me suggestions in the comments.