I was quite surprised to find the software backing this isn't open source: https://www.lend-engine.com/

I had expected it to be an open source with paid hosting/support model. But at 25 USD/month for 500 items and 50 USD for over 2000 items, it's pricier than I had expected!

But this Library of Things seems fantastically cheaper than, say https://www.libraryofthings.co.uk/, which will rent you a hedge trimmer for £13 a day rather than £4 per week!