I am having a problem getting the boost regex icu example code to link on linux. I am on Redhat Linux 9, using gcc 3.4.4. I downloaded the src ICU package and built and installed it as root in /usr/local with no problem. I downloaded boost_1_33_1 and got it to build and install with no problem. I first did a configure telling it where my ICU was located. As it built it stated it was being built with ICU in /usr/local/include. So now I got to build the regex/example code. There is a program under snippets/icu_example.cpp. I went into that example and forced the code to compile the main using the icu. By that I mean I took out the #ifdef BOOST_HAS_ICU and deleted the code around the main that printed "<NOTE>ICU support not enabled..." The code compiles, but when it goes to link I get all these unresolved external references..e.g. ../../../bin/boost/libs/regex/example/icu_example.test/gcc/debug/threading-multi/icu_example.0(.text+0x3e9): In function 'extract_greek(icu_3_6::UnicodeString const&)': snippets/icu_example.cpp:61 undefined reference to icu_3_6::UnicodeString::UnicodeString(unsigned short const*, int)' I get other cases where for example.. ../boost_1_33_1/boost/regex/icu.hpp:1001: Undefined reference to 'icu_3_6::UnicodeString::UnicodeString()' (It seems that maybe the prefix icu_3_6 is being added in the class resolution when creating this .o but was not used in the creation of the .a boost/icu libraries. ) Any idea how to fix this? Gary