There are e-readers and DRM-free electronic libraries.

It's slower than nftables.

Per Dr. Marshall Kirk McKusick (as announced in one of the recent BSD conferences), No Starch Press will be publishing the third edition of the Design and Implementation of the FreeBSD Operating System book sometime later this year.

Yeah. My favorite are books that guide you through implementing complex systems projects from scratch, like Nora Sandler's "Writing a C compiler", or Sy Brand's "Building a Debugger". I wish they produced A LOT more of them.

I buy ebooks straight from publishers like Nostarch and Leanpub. (In fact, I have an older edition of this book). There are a few books that are sold directly by the authors too. All of them DRM-free.

I actively avoid publishers and sellers who don't respect me as a consumer/reader. People need to start demanding better deals, or else we'll end up with monopolies that won't think twice about deleting books in your custody that you purchased from them.

I wish I had more of them. I maintain a modest library made out of real paper and I'm so glad No Starch still has good quality paper and excellent binding. I have a few of the more recent print on demand O'Reilly books but they feel more like cheap print outs I could have done myself. Unfortunately they are just so expensive so I do have to be very selective.

Was thinking I had missed an entire edition of Pathfinder for a moment upon reading the title

Nftables has a really good doc site https://wiki.nftables.org/wiki-nftables/index.php/Main_Page. I wouldn't rely on any book