I get the same error from both nhc98 and ghc when trying to use hat on solaris. Do you know what I'm likely to be missing? legion:haskell> hmake -hat Insort hat-trans Insort.hs Wrote TInsort.hs /dcs/biorepos/FuncProg//bin/nhc98 -c -package hat -o TInsort.o TInsort.hs /dcs/biorepos/FuncProg//bin/nhc98 -package hat -o Insort TInsort.o Undefined first referenced symbol in file ntohl /dcs/biorepos/FuncProg//lib/nhc98/sparc-solaris2/libHShat.a(hat.o) htonl /dcs/biorepos/FuncProg//lib/nhc98/sparc-solaris2/libHShat.a(hat.o) ld: fatal: Symbol referencing errors. No output written to Insort collect2: ld returned 1 exit status legion:haskell> hmake -hat -ghc Insort hat-trans Insort.hs Wrote TInsort.hs ghc -c -package hat -o TInsort.o TInsort.hs ghc -package hat -o Insort TInsort.o Undefined first referenced symbol in file ntohl /dcs/biorepos/FuncProg//lib/ghc-5.02/libHShat.a(hat.o) htonl /dcs/biorepos/FuncProg//lib/ghc-5.02/libHShat.a(hat.o) ld: fatal: Symbol referencing errors. No output written to Insort collect2: ld returned 1 exit status I'm using hat2.00, nhc98-1.14 and ghc-5.02 on a SunOS legion 5.8 Generic_108528-14 sun4u sparc SUNW,Ultra-Enterprise. ld is GNU ld 2.11.2. Also, just for future, the echo.c prog to simulate echo was missing from the scripts directory when installing hat, so I used the one from nhc98. Amanda