First of all: You don't need to download any software if you just want to make a wiki! For that, simply try the demo, or sign up for a free account.
But if you do want to run Luminotes on your own server, here is the necessary software:
It is licensed under the terms of the GNU GPL. To use this software, you'll need a Linux machine with Python and PostgreSQL. More details, including installation instructions, can be found within the included INSTALL file.
If you have any problems or questions, please let me know. See my contact info for details.
The download link above is the most recent stable release of Luminotes server. If you're interested in getting your hands on the development version of Luminotes, then you should use the Luminotes Mercurial source code repository. You can either clone a local copy of the repository or just browse the source code online:
I should emphasize that this is the development version of Luminotes. This means it's intended for developers and likely contains untested or unfinished features. If you want to run a production server, download the stable release above rather than using the development version.
Found a bug? Want to submit a patch? Please see my contact info.