Review on Horde Application Framework by Rob Parsons

I like how easy it was to get up and running with, as well as its extensibility.

It's also very powerful if you need that kind of flexibility for your project. There are some things about HAF that could be improved - especially around debugging issues when using multiple servers (it can sometimes be difficult to see what code has executed where). We're solving our own problems by implementing this but we've been able to do so without having to write any custom software or build out an entire infrastructure from scratch.