Workit is a blatant rip off of Doug Hellmann's virtualenv wrapper:
http://www.doughellmann.com/projects/virtualenvwrapper/

I just wanted something that wasn't wrapped out virtualenv since most of my
projects are PHP or other type things. 

The nice thing is that it allows you to setup a postactivate command which can
setup your environment for you. Below is a sample postactivate script which
performs several actions upon getting into the project. 

> $ workit someproject
> 
> #! /bin/zsh
> 
> # variables needed for some script
> export JS_PATH="$PROJ_PATH/src";
> 
> # define a custom function we can use to launch tests
> qunit() { chrome "http://project/javascript/tests/runtests.html" }
> 
> # run ctags so vim is up to date when we start working on a project
> ctags -f $PROJ_PATH/tags -R $PROJ_PATH/src 2> /dev/null &!
> 
> # use the reusable methods for start/stop serives. This project shuts down mysql
> # and starts up pgsql for use
> zmysql_stop
> zpgsql_start

You can also run a postdeactivate to shut down or clear settings from the
project. This is run whenver the command `deactivate` is run or you switch to
another project. 

Projects are directories within the directories specified in the WORKIT_HOME.
You can create an array of locations to used. Any directory in these paths will
be used to complete/switch projects.