just to clarify I am not the amazing dev behind this project. Val Erastov has done an amazing job of bringing parametric 3d solid modeling to the web. He has been worries to move from nurbs to brep and that is an admirable goal with real practical application.
jSketcher and web-cad.org are cross platform cad tools that enable people to design 3d models with out having to install any software locally. A web browser is all that is need.
That simple change is a paradigm shift for 3d modeling software and cad packages. The fact that it is open source and can be run on a variety of platforms is a change from existing packages.
I really hope you give the jSketcher a shot and send this guy some cash. There is a PayPal link at the bottom of the page at http://web-cad.org . It would be awsome to support this project and get cad tools in to the hands of any one with a web browser.