sonicr demo.exe: Self-extractor for Japanese Sonic R trial version (https://web.archive.org/web/20131030110035/http://sega.jp/pc/sonicr/trial.shtml)
sonicr_1998.exe: 1998 release of Sonic R
sonicr_2004.exe: 2004 multi-platform re-release of Sonic R
sonicr_net.exe: Official/final network patch from sonicr_update.zip
sonicr_protonet.exe: Earlier revision of network patch from SEGA Twin Pack
sonicr_semivanilla: 1998 release of Sonic R with CPU fix and CD check bypass patches (required for modern systems)

patchers/
SR_NET.EXE: earlier version of Sonic R network patch from SEGA Twin Pack (see https://www.youtube.com/watch?v=DLuUjgU70J0 for differences)
sonicr_update.zip: Sonic R network patcher (final/official from SEGA's website). Needs to be placed in same directory as SONICR.EXE to work.