The following repsonsibilties, by author, were found in the current revision of the repository (comments are exluded from the line count, if possible).
andreask is mostly responsible for
generic/tclExecute.c (3 eloc)
generic/tclAssembly.c (3 eloc)
dgp is mostly responsible for
generic/tclCompile.c (322 eloc)
generic/tclBasic.c (254 eloc)
generic/tclIO.c (173 eloc)
generic/regc_nfa.c (155 eloc)
generic/tclCompCmds.c (94 eloc)
generic/tclCompCmdsSZ.c (78 eloc)
generic/tclExecute.c (76 eloc)
generic/tclCompCmdsGR.c (65 eloc)
generic/tclCmdIL.c (59 eloc)
generic/tclInterp.c (56 eloc)
dkf is mostly responsible for
generic/tclCompCmdsGR.c (1945 eloc)
generic/tclExecute.c (1018 eloc)
generic/tclCompCmdsSZ.c (842 eloc)
generic/tclCompile.c (470 eloc)
generic/tclOptimize.c (350 eloc)
generic/tclCompCmds.c (295 eloc)
generic/tclEnsemble.c (281 eloc)
generic/tclBinary.c (189 eloc)
generic/tclCompile.h (97 eloc)
generic/tclBasic.c (84 eloc)
jan.nijtmans is mostly responsible for
unix/tclUnixFCmd.c (130 eloc)
generic/tclStubInit.c (107 eloc)
generic/tclDecls.h (104 eloc)
generic/tclUniData.c (95 eloc)
compat/zlib/contrib/minizip/iowin32.c (85 eloc)
generic/tclIntDecls.h (71 eloc)
unix/dltest/pkgooa.c (64 eloc)
generic/tclExecute.c (43 eloc)
unix/tclUnixNotfy.c (42 eloc)
generic/tclOODecls.h (42 eloc)
jenglish is mostly responsible for
unix/tclUnixChan.c (62 eloc)
joe is mostly responsible for
unix/tclUnixChan.c (11 eloc)
max is mostly responsible for
unix/tclUnixSock.c (11 eloc)
win/tclWinSock.c (4 eloc)
generic/tclIOSock.c (1 eloc)
mig is mostly responsible for
generic/tclExecute.c (242 eloc)
generic/tclCompCmds.c (69 eloc)
generic/tclBasic.c (67 eloc)
generic/tclCompile.h (29 eloc)
generic/tclCompile.c (29 eloc)
generic/tclProc.c (21 eloc)
generic/tclInt.h (12 eloc)
generic/tclTomMathInterface.c (3 eloc)
generic/tclIORTrans.c (3 eloc)
generic/tclEnsemble.c (3 eloc)
oehhar is mostly responsible for
win/tclWinChan.c (57 eloc)
unix/tclUnixNotfy.c (8 eloc)
win/tclWinSerial.c (7 eloc)
win/tclWinInt.h (1 eloc)