Its a daunting task but I really feel someone has to do it before any real headway can be made with bug fixes and in my dream world the glorious day when us die hard ACK fans collaborate on some sort of source documentation and perhaps even a complete rewrite of all the source code so all the bug fixes and features that Chris had to sort of hack in will actually be planned for and truly built into it. AAND maybe even use the most recent version of Pascal to do it!
As far as I know the most recent descendent seems to be Free Pascal. http://en.wikipedia.org/wiki/Free_Pascal Last updated this year. And according to the wiki it tries to retain backwards compatibility with older code such as Turbo Pascal and Delphi.
Quoted from wiki:
Free-Pascal WebsiteIn addition to its own Object Pascal dialect, Free Pascal supports, to varying degrees, the dialects of several other compilers, including those of Turbo Pascal, Delphi, and some historical Macintosh compilers. The dialect is selected on a per-unit (module) basis, and more than one dialect can be used to produce a single program.
A member of the write once, compile anywhere campaign, Free Pascal is available for many architectures and operating systems