Did you work with Brian Fox before becoming the primary maintainer of the language?
Brian and I worked together for several years before he moved on to other things. The versions through BASH-1.13 were collaborative releases.
What is/was your working relationship with Brian like?
Our working relationship was very good, especially considering we met in person only once, in 1990. We were heavy users of UNIX `talk' and `ntalk', which allowed real-time two-way communication over the Internet back then, and made good use of email and the occasional long distance phone call.
We still stay in touch.
What prompted the making of Bash in the first place?
When Richard Stallman decided to create a full replacement for the then-encumbered Unix systems, he knew that he would eventually have to have replacements for all of the common utilities, especially the standard shell, and those replacements would have to have acceptable licensing.
After a couple of false starts (as previously mentioned), he hired Brian Fox to write it.
They decided early on that they would implement the shell as defined by the Posix standard, and used that as a specification.
Was there a particular problem that the language aimed to solve?
In BASH's case, the problem to be solved was a free software version of the Posix standard shell to be part of the GNU system.
The original version of the shell (Steve Bourne's version) was intended to overcome a number of the limitations of the Unix shell included in versions up to the sixth edition, originally written by Ken Thompson.
Why did you take over as the language's primary maintainer 3 years after Fox created the language?
Brian wanted to move on to other things, and I was a developer willing to take it on and experienced with the code. Brian and the FSF trusted me with the program's future.
What prompted the writing of the GNU Bash Reference Manual and the Bash Reference Manual?
Any good heavily-used program needs good reference documentation, and BASH is no exception. I originally wrote the documents to support my local users, and they were folded into "official" releases along the line.