I have downloaded the archive from the Sleepycat website and I can't
build the Berkeley XML database on FreeBSD 5.4.

What is the problem on the build of Xerces (included on the archive) :

export TRANSCODER="IconvFBSD"
export MESSAGELOADER="INMEM"
export NETACCESSOR="Socket"
export THREADS="none"
export BITSTOBUILD="32"
export CC="gcc"
export CXX="g++"
export CXXFLAGS=" -w -O -DPROJ_XMLPARSER -DPROJ_XMLUTIL -DPROJ_PARSERS
-DPROJ_SAX4C -DPROJ_SAX2 -DPROJ_DOM -DPROJ_DEPRECATED_DOM
-DPROJ_VALIDATORS -DXML_USE_NATIVE_TRANSCODER
-DXML_USE_INMEM_MESSAGELOADER -DAPP_NO_THREADS -DXML_USE_NO_THREADS
-DXML_USE_NETACCESSOR_SOCKET "
export CFLAGS=" -w -O -DPROJ_XMLPARSER -DPROJ_XMLUTIL -DPROJ_PARSERS
-DPROJ_SAX4C -DPROJ_SAX2 -DPROJ_DOM -DPROJ_DEPRECATED_DOM
-DPROJ_VALIDATORS -DXML_USE_NATIVE_TRANSCODER
-DXML_USE_INMEM_MESSAGELOADER -DAPP_NO_THREADS -DXML_USE_NO_THREADS
-DXML_USE_NETACCESSOR_SOCKET "
export LDFLAGS=" "
export LIBS=" "
configure --prefix=/usr/home/sto/tmp/dbxml-2.1.8/install

If the result of the above commands look OK to you, go to the directory
/usr/home/sto/tmp/dbxml-2.1.8/xerces-c-src_2_6_0/src/xercesc and type
"gmake" to make the XERCES-C system.
Building Xerces
"Makefile.incl", line 64: Missing dependency operator
"Makefile.incl", line 66: Need an operator
....
....
"Makefile", line 250: warning: duplicate script for target
"(INMEM,ICU)" ignored
"Makefile", line 251: Need an operator
"Makefile", line 252: Need an operator
"Makefile", line 253: Missing dependency operator
"Makefile", line 254: warning: duplicate script for target "ifeq"
ignored
"Makefile", line 254: warning: duplicate script for target
"(INMEM,ICU)" ignored
"Makefile", line 255: Need an operator
"Makefile", line 256: Missing dependency operator
"Makefile", line 257: warning: duplicate script for target "ifeq"
ignored
"Makefile", line 257: warning: duplicate script for target
"(INMEM,ICONV)" ignored
"Makefile", line 258: Need an operator
make: fatal errors encountered -- cannot continue

Are you using GNU make? That is what is required.

Ron