DescentBB

Please assist. I'm on Linux.

The HOG tools I know of only work in Windows (or perhaps they work under WINE).

Yeah, in fact, ALL of Descent editing tools are made to work on either DOS or Windows, exclusively.
Up to today, it doesn't exist any Descent tool designed to work natively on Linux.

But as Krom says, you might want to try Wine or maybe a Virtual Machine with Windows on it or even a dual-boot installation.

How about dosbox? Could it get the job done?

Yeah, a DOS based tool could probably work in dosbox. But then the question is finding one, by the time D2 rolled around pretty much everything was win32.

The file format for .HOG files is trivial (an uncompressed archive):

http://www.descent2.com/ddn/specs/hog/

Anybody who has taken a course covering file manipulation in any procedural or object-oriented language can write an extraction program easily. The real question is which content files did you want to manipulate and what exactly did you want to do with them.

Exactly as akula said, depending on which type of files you want to manipulate, you may get to a point where you can't do anything but use the Windows Descent tools (i.e. for editing polymodels, robots, etc, you may need to use DM Robot Construction Kit, that is a Win32 application).

Fortunately, for level edition there is the old Devil that works on DOSBox and the new SDLDevil source code, if you want to port it to Linux.