What are some alternatives?
When comparing SLIM21 and LibraryH3lp, you can also consider the following products
LIBRARIAN - Comment on any arXiv paper
Apollo ILS/LSP - The Apollo ILS (Integrated Library System) was designed from the ground up by practicing librarians to be a hosted ILS for public libraries.
Eloquent Library - Eloquent Library contains all the functions available in traditional Integrated Library Systems, plus everything required to build and maintain a virtual library.
Alma - Meet Alma, a modern and affordable integrated student information system (SIS) and learning...
Follett Destiny Library Manager - Follett Destiny Library Manager is a complete library management system that can be accessed from anywhere.
LibraryWorld - Library automation solution