From lurking in the German mikrocontroller.net forum there are a few hobby alternatives like - EleLa : http://www.mmvisual.de/elela/ [] - PartDB : https://github.com/Part-DB/Part-DB-server

The page on the forum wiki is https://www.mikrocontroller.net/articles/Elektronik_Lagerver... [] and it speaks mostly about EleLa.

[*] these links are in German.

EleLa is a desktop app for Windows and Linux written in FreePascal with Lazarus PartDB isa PHP server for self hosting