There are tons of different open source and pay javascript/html/css addons that exist out there that to evaluate you need to download, edit and play around with

There are tons of different open source and pay javascript/html/css addons that exist out there that to evaluate you need to download, edit and play around with. This is a much easier way to let developers evaluate a project without having to go through that hassle. This is an area where right now most projects seem to rely on (the awesome) jsFiddle - but having things on your own server makes sense in many cases.