Update
Mayocat-shop was an attempt at building an easy to use open-source marketplace platform. It's a retired project as of 10/02/2017, as the project did not gain enough traction and I've moved on to other ventures. While bugfixes might make it to this repository (as there are production sites running on mayocat), I have no plan to continue development and add new features. If there is interest in continuing development of the platform, I'll gladly hand over commit and administrative rights to potential contributors.