The cygwin environment is mainly identical to unix except that java and javac use
semicolon for classpath separator instead of colon.  I have modified the ant shell
script to take this into account.  Not extensively tested but works on my system.

Apologies if this submission is halfbaked.  This is a 'scratch an itch' situation for
me.  Diff follows and complete version is attached.

Index: bin/ant

bash.exe-2.02$ diff /usr/ant/bin/ant-orig /usr/ant/bin/ant
2a3,4
> # modifications by lucas@gonze.com Feb 20, 2001 to make this run under Cygwin.
>
40c42,48
< LOCALCLASSPATH=`echo $ANT_HOME/lib/*.jar | tr ' ' ':'`
---
> if [ "$OSTYPE" = "cygwin32" ] ; then
>     LOCALCLASSPATH=`echo $ANT_HOME/lib/*.jar | tr ' ' ';'`
>     CLASSPATHSEP=";"
> else
>     LOCALCLASSPATH=`echo $ANT_HOME/lib/*.jar | tr ' ' ':'`
>     CLASSPATHSEP=":"
> fi
43c51
<   LOCALCLASSPATH=$CLASSPATH:$LOCALCLASSPATH
---
>   LOCALCLASSPATH="${CLASSPATH}${CLASSPATHSEP}${LOCALCLASSPATH}"
48c56
<     LOCALCLASSPATH=$LOCALCLASSPATH:$JAVA_HOME/lib/tools.jar
---
>     LOCALCLASSPATH="${LOCALCLASSPATH}${CLASSPATHSEP}${JAVA_HOME}/lib/tools.jar"
52c60
<     LOCALCLASSPATH=$LOCALCLASSPATH:$JAVA_HOME/lib/classes.zip
---
>     LOCALCLASSPATH="${LOCALCLASSPATH}${CLASSPATHSEP}${JAVA_HOME{/lib/classes.zip"