insert-coin's a lightweight & simple image-uploading/URL-shortening service.
First, drop everything in a directory on your web-server (root, non-root, it doesn't matter). Secondly, create two directories-- "p/" and "u/"-- that are accessible and modifiable by your web-server user. Finally, you probably want to edit "res/config.php". Then, profit!
Make sure to configure your web-server to use PHP with index.php, beam.php, url.php, conjure.php, and anything in the u/ directory that you'll create.
Everything (unless mentioned otherwise) is under the Cooperative Software License, as seen at https://coinsh.red/csl/csl.txt, or in LICENSE.txt.
TL;DR: You can share, modify, and sell insert-coin at your whim-- as long as you do so with corresponding source-code and aren't a bourgie. If you run a modified insert-coin on your web-server, make sure to offer your users the source-code! :)