Suggest a 'Knowledge Base' PHP script

**Wanna Earn $10 in 5 Minutes?** I would like you to suggest a Professional "Knowledge Base" scripts system, with Complete Admin section for my company. The system must be compatible with "PHP/MySQL". Note: I am not looking for something to be built from "scratch".. I do not want to re-invent the wheel. You will only post a link to the "Knowledge Base" site, and another one to their "Demo". And tell me why you like it. Doesn't matter if it's a Paid or Free System, as long as it serves the purpose. I will pay $10 for the best suggestion - which my company decides to go with. (Please submit the links first - coder will be chosen after full test of systems). Here are the Features that I am looking for in the needed script: **USER INTERFACE:** View/search/sort categorized FAQs View related questions list Email selected question to a friend Ask and Submit new questions Convenient Suggested Answers list after submitting new question title (Saves time) View personally submitted questions list Check status of your questions Automatic email when questions is answered **ADMIN INTERFACE:** Add / Edit / Delete Questions Sort & search Questions Change status of questions Add / Edit / Disable / Delete representatives List / Add / Disable / Delete categories Reassign questions / categories / reps thanks for checking