What are some alternatives?
When comparing Helpman and ProProfs Knowledgebase, you can also consider the following products
Tenfold - Tenfold is a mobile game that is designed primarily to be played by iPhone users. The game is available on the app store. The tagline of the game is "twenty seven numbers, endless puzzles. Read more about Tenfold.
ZenDesk - Zendesk is a beautiful, lightweight help-desk solution.
statuspage - A simple self-hosted status page site with an API written in Django under the BSD license.
Document360 - Self-service knowledge base software focused on SaaS Products & Enterprise Software Projects.
YUNO - YUNO is a web data driven company focussed on solving customer challenges in web data discovery and extraction space.
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community