export JAVA_HOME=$PWD/j2sdk&j2sdk-version; : This command sets the location of the working java. export ALT_BOOTDIR="$JAVA_HOME" : This command set the compiler variable that will execute the java compiler when needed during make. export ALT_MOTIF_DIR=$SRC : This sets the variable that points to where you unzipped the motif headers. export ALT_MOZILLA_PATH=$SRC : This sets the variable that points to where you unzipped the mozilla headers. export ALT_DEVTOOLS_PATH="/usr/bin" : This changes the default to the correct value. export ALT_MILESTONE="blfscompiled" : This will help you identify this compiled version of java by appending this to the version in the output to "java -version". export BUILD_NUMBER=`date +%s` : This will help you identify this compiled version of the runtime environment and virtual machine by appending this information to the version in the output to "java -version". export DEV_ONLY=true : This command eliminates compiling the documentation and eliminates a dependency for rpm. export OTHER_LDFLAGS="-lpthread" : This command corrects compiling errors related to the pthread variables. unset JAVA_HOME : This clears the JAVA_HOME variable and prevents misdirection during compile. unset CLASSPATH : This clears the CLASSPATH variable and prevents misdirection during compile. export OTHER_CFLAGS=${CFLAGS} : This makes j2sdk compile using your CFLAGS for optimizations. export OTHER_CXXFLAGS=${CXXFLAGS} : This makes j2sdk compile using your CXXFLAGS for optimizations. unset CFLAGS : Now that the optimizations are loaded, this clears the variable. unset CXXFLAGS : Now that the optimizations are loaded, this clears the variable.