Competitors There are a few competitors out there that do something very similar (see https://ruttl.com/, https://usepastel.com/, https://bugherd.com/, https://www.markup.io/). This seems to suggest that there seems to be a general market for such a product. Source: over 1 year ago

Yes, we used Pastel https://usepastel.com and it was very nice overall. - Source: Hacker News / almost 2 years ago

I have 827 (thank you librarything.com for the catalogue) and 7 dictionaries in four languages accumulated over 50-odd years. I have several matching sets I’ve bought as they were issued. You just have to (a) buy books and (b) live a long time. Source: 12 months ago

I use librarything.com to keep track of books I read. One of the things I like most about the site is that it basically works like your own personal library card catalog. You can create "collections" as well as tags to organize your books. You can easily add books by edition, format, or ISBN to your library. And if you have physical books, you can scan the barcodes to add them to your library instead of entering... Source: about 1 year ago

Take a look at librarything.com, probably perfect for small libraries. Source: over 1 year ago

i'll also put in a plug for librarything.com. I prefer it way more than goodreads. It feels less more indie and far smaller. Source: over 1 year ago

I believe you can make comments vs. Private comments on librarything.com. You can also set your entire library to private. Source: over 1 year ago