Available here: http://people.cs.uchicago.edu/~jacobm/arc.mzscheme370.patch This is an unofficial patch against arc0.tar that "Works for Me" to get arc running on mzschemes from about 350 or so up to the most recent official releases (doesn't work for 3.99.x, though). Use at your own risk, etc. To install: $ wget http://people.cs.uchicago.edu/~jacobm/arc.mzscheme370.patch $ patch -d /path/to/my/local/installation/of/arc0 < arc.mzscheme370.patch One reason to use a newer mzscheme: on my laptop, $ time echo "(quit)" mzscheme352.5 -m -f as.scm Use (quit) to quit, (tl) to return here after an interrupt. arc> real 0m6.583s user 0m4.503s sys 0m0.389s $ time echo "(quit)" | mzscheme371.3 -m -f as.scm Use (quit) to quit, (tl) to return here after an interrupt. arc> real 0m1.570s user 0m0.818s sys 0m0.089s |