jCad is an electrical CAD system, written in java. Its main characteristics are:

Documentation consists of a Users Guide and a Reference Manual. Earlier versions of these are available here.
The jCad software is shipped as a tarball for Linux/Unix and a Zip archive for Windows. These packages contain a startup script plus the jar, libraries, fonts and configuration files. These two versions are only slightly different - the startup script and the config.g files differ because of file and script conventions, but the .jar executable, font and lib files are identical. (old distributions)
There is a small and very simple collection of example drawings here.
The file Changes.txt describe version differences.
I can not offer any real support, you have to use the software as it is. Or help me. / Mats Barkell