FilenameFilters you can use in your own Java programs with
File.list( FilenameFilter f ). They can also be used
standalone as fancy dir commands.
They come with Java source and include:
AllButSVTDirectoriesFilter all but .svn directories
AllDirectoriesFilter  gets all directories
AllFilesFilter        gets all files
ClamFilter            simple wildcard
DirListFilter         gets a list of directories
EndsWithFilter        gets files whose names end with a given string.
EverythingFilter      gets everything
ExtensionListFilter   gets files matching a list of extensions
                      (formerly ExtensionFilter)
FileLengthFilter      gets short or long files
FileListFilter        gets a list of files
                      (used to be called ListFilter)
FilenameLengthFilter  gets short or long filenames
JunkFilter            used to find junk files by name, extension,
                      startsWith or endsWith lists.
MultiFilter           combines other Filters with
                      "consider", "must" and "never".
NoFootFilter          accepts *.html but not *.foot.html
RecentFilter          filters based on lastModified date
RegexFilter           filters with Regex expressions.
RecentFilter          filters based on lastModified date
RegexFilter           filters with Regex expressions.
StandAndEndWithFilter include/exclude depending on start/endings of filenames
StartsWithFilter      gets files whose names start with a given string.
Why that orange disc icon?  It represents a photographic
filter that filters light, is an analogous way the filter
class filters files.