I guess there is a little bit of adaptation required for using the latest JDK:
[...]
freemind/freemind/main/XMLElement.java:484: as of release 1.5, 'enum' is a keyword, and may not be used as an identifier
    [javac] (try -source 1.4 or lower to use 'enum' as an identifier)
    [javac]         while (enum.hasMoreElements()) {
    [javac]                ^
[...]

Cheerio, Guillaume