I started down this road with a few books about two years ago, and I have so many now on my list to read that I hardly ever get to reading a modern book.
I read a lot from Standard Ebooks. But one thing to keep in mind with them- they do edit the books to make changes for readability. Not necessarily a big deal, but something to know.
https://standardebooks.org/about/what-makes-standard-ebooks-...
https://www.bloomsbury.com has drm free stuff, and after https://news.ycombinator.com/item?id=42811332 i respect them even more.
Also might be worth scanning old mentions of such https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
Having commercial publishers that will sell you high quality books without DRM is brilliant and I'll always support that.
Nonetheless, I'll promote an author of both non- and fiction ebooks I've bought from, Michael W Lucas [0].
and although I already previously had the idea of showing books from gutenberg but your idea made me find more importance in it and I ended up doing so in two different implementations: https://guten.mirror.forum and https://gutencf.mirror.forum, so I thank you for that!
[Offtopic: I am/was also surprised to see that there is a lack of API or platforms if suppose I created this app and I wanted to give users genuine ways to pay. Aside from the walled gardens of Kindle or specific apps, I am unable to give my users a way to just search books, pay for them and download it (atleast to my understanding at the moment) which is a sad thing :-( ]
I hope people are able to give love to my submission at [0] / the link down below. Cheers and take care and have a nice day if a real human is being out there reading this :-D
Hope you like or enjoy it and find it useful!