History of Computing
I have been interested in the history of computing and hacking (in the classic sense) and have collected many significant books (SICP, Hopcroft, Aho, Ullman, etc), papers (eg Church's lambda calculus), documents (early MIT PDFs, important historical text files, etc), programs, etc from the past. I am particularly interested in the design and evolution of programming languages from the dynamic (LISP, Scheme, etc) and static (Algol family: C, Pascal, etc).
I am also interested in the philosophy of computing (Church, Quine, Russell, Kant, etc) and the border between philosophy, mathematics, and computational theory.
To run classic software, I have built a VirtualBox image that runs Windows 2000 in order to have a way to run classic MS-DOS and Windows programs on Linux. I have a particular interest in program from 1987 and earlier, along with some from later.
I have used many older operating systems in emulation, including booting up the Incompatible Timesharing System (ITS) in a PDP emulator. I have also gotten a version of GNU Emacs from 1987 running on modern Linux.