Squeaky is a project mainly written in PHP and JAVASCRIPT, it's free.
A web proxy based on A2 / PHProxy
squeaky is a simple web proxy based on A2 which in turn is based on the apparently defunct PHProxy.
For a more popular, but not open source, proxy see glype.
A2 is release under GPL, so squeaky follows. However, as A2 does not mention a specific GPL version, per paragraph 9, I choose to release squeaky under GPL v2.