I want to start a "rate my"-style site. The rated objects are mostly texts. I want it to be rather simple. Features I need: object rating (thumb up, thumb down) object comments object tags related object presentation based on tags user authentication and management private message system sanity checks for text inputs (i.e. prevention of code injections) cache open source runs on GNU/Linux I would gladly take something that is tailored for my scenario but a generic framework would be fine too. I simply don't want to write stuff like user authentication that is been written a million times and risking security flaws. Programming language is irrelevant but python/php preferred.