The convention on Linux is that extracting a tarball named
bm253.tar.gz will create a directory named bm253/ with
other files within. It's extremely annoying to many
when they occassionally come across a tarball that dumps
everything in the current directory because if there
were a lot
of existing files already it can be extremely difficult
and move the newly extracted files.
Note that the open source release howto here on SourceForge
makes this same point very strongly. Please create
files in the standard way that users expect. Using GNU
tar -zcvf bm253.tar.gz bm253/
tar -zcvf bm253.tar.gz .