Cumulate Draw – Open Source online drawing application
Cumulate Draw is an Open Source drawing application. You can either use it online (on an ad supported basis), or apply for a download of the source code for non-commercial use.
It’s a pretty nice package. Simple to use and with all the right features you’d expect (as well as a shape editor to create your own design elements). A worthy and faster alternative to Gliffy, even though there’s no shared editing. Check it out.