Dia draws your structured diagrams: Free Windows, Mac OS X and Linux version of the popular open source program[web search]
The current Dia release has been tested successfully on Windows 8.1, 8, 7, Windows Vista and Windows XP, Linux and Mac OS X.
The download page provides download packages for Mac OS X and Linux as well as information about Dia on older Windows versions.
If you encounter any problems with dia, please read through the FAQ first.
You should also check the bug reports.
Dia is free software available under the terms of the GNU GNU General Public License, the GPLv2.