On Fedora/RHEL systems, I see w3m-0.5.3 cannot be built successfully with parallel make. There are 2 problems I found. One for HELP_TARGETS files in scripts/Makefile.in file. Another for w3mimg/Makefile.in file. Attached patch will fix those 2 makefiles to allow parallel make compilation.
allows parallel make compilation
Fixed with different patch in Debian:
http://anonscm.debian.org/gitweb/?p=collab-maint/w3m.git