The Inform's Designer Manual, is it still useful?

Other than the fact, that this is a comprehensive text, I have a question about “The Inform Designer’s Manual”.

Inform 7 has been around for a while and under the hood, I think it still compiles the IF to the Inform 6 compiler. Correct me if I’m wrong.

Because of this, it makes sense that the book could be useful as a reference. However, since Inform 7 is what is actively being developed, will the older Inform 6 process eventually be abandoned? Is it safe to assume, that because of the design philosophy behind Inform 7, that within the near future, the system will be redesigned?

Should I just concentrate more on learning Inform 7 than to bother with the more classical programming method? (I’m not a serious author, I just dabbled a little with text adventures and found some fun stories out there and thought about trying to make a few puzzles. Inform 7 looks like the most interesting design concept. I also recently looked at parsers, but decided it’s a little too complicated to build from scratch.).

What are some opinions on this and the usefulness of the book?

There is no intention that I’m aware of to stop using the I6 compiler in I7. The I6 compiler will continue to be maintained.

The I6 library was for a time abandoned, however David Griffith has picked it up again.

I personally love I7, and think its rules system is a much better way of organising IF than I6’s object oriented stuff. But to do low level stuff I use I6 too. I can’t imaging going back to the old I6 object and actions system though.

It’s not impossible, I suppose, but it isn’t going to happen in the near future, and it’d be such a major departure that it’d have to be called Inform 8.

You can do almost everything in I7 without learning any I6 at all. And for the small remainder of things, you can usually find an I6-fluent person to help out. If you’re just starting out and I7 suits you better, I wouldn’t worry about I6 for now.

To someone who’s not intending to code in I6, the Craft of Adventure sections of the book are still worthwhile. Some of the design-theory stuff therein is a bit dated, but some remains highly relevant; and either way, it’s a good read.