CodeIgniter

CodeIgniter is a PHP framework, which is pretty fast and easy to learn.
Not many years ago I didnt really care much about frameworks, i had my little nice set of functions I collected during the years, and I didn't have much problems editting and creating new sites, but for some reason I decided to try frameworks.
I have always liked open source, so I really liked the idea of people sharing their awesome functionality, and if you dont have much experience with MVC starting with CodeIgniter is a great option! It takes like 30 minutes to read the begginer documentation, and then you have awesome reference, you may develop a bit slower first, but later you will do it faster! And in a very scalable way!
What is nice about using frameworks is that if it's a project where more than one person works (Including MVC advantages already) you know what to edit, you know what to do already, no need to lose time reading what other programmer structure is!
It has many many advantages, I will just say, i recommend it!
I have used for my last projects and it works flawlessly! I also like sharing my own libraries :) I made an excel plugin, to export an xls file.
Anyways! If you develop on PHP, i would say this is a very nice tool!