Last week I had given useful cheats sheets , which contains useful information for developer which gives quick reference to programming language.
Now here are some new cheat sheets for HTML 5,
HTML 5 Cheat Sheets
References :
I have found awesome collections of cheat sheets on internet which gives quick reference guide of various functionality.
Here are some good cheats links,
osTicket is a widely-used open source support ticket system. 
It is simple, lightweight, reliable, open source, and easy to setup and use. The best part is, it’s completely free.
Phplist is an open-source newsletter manager. phplist makes sending newsletters easy, professional and managable.
Phplist has many features like,
Open Web Messenger is an open source chat application for support. 
It enables one-on-one chat assistance in real-time directly from your website.
Ultimate Web Resources 