What are some alternatives?
When comparing SLIM21 and Boopsie for Libraries, you can also consider the following products
LIBRARIAN - Comment on any arXiv paper
Mandarin Library Automation - Mandarin Library Automation helps librarians and teachers to bring relevant, current information to libraries and classrooms.
LibraryH3lp - LibraryH3lp provides a flexible, affordable customer service software platform for libraries, educators, and non-profits that combines website chat, texting, email, and knowledge bases.
LibraryWorld - Library automation solution
Eloquent Library - Eloquent Library contains all the functions available in traditional Integrated Library Systems, plus everything required to build and maintain a virtual library.
LIBSYS7 - LIBSYS7 is a library management software that offers solutions in library automation, RFID and digital resource management.