Ensure that system environment variable PATH includes the location of all the compilers mentioned above.

Download the source code of ICU version 3.6 for C from http://icu.sourceforge.net/download/3.6.html#ICU4C

Add the following line in the configuration file source/config/mh-hpux-acc to include the appropriate C++ runtime libraries:

DEFAULT_LIBS = -lstd_v2 -lCsup_v2 -lcl

At the shell prompt, execute the following commands:

gunzip -d < icu4c-3_6-src.tgz | tar -xf - 
cd icu/source/ 
chmod +x runConfigureICU configure install-sh
runConfigureICU HP-UX/ACC --disable-64bit-libs --disable-threads
gmake 
gmake check 
gmake install

Set the environment variable LD_LIBRARY_PATH to point to the location of ICU. HP-UX uses the environment variable LD_LIBRARY_PATH to search for dynamically linked libraries.