* Nearly all archives now have file extenders:
xxx.spk: Spark archive
xxx.zip: Zip archive
xxx.arc, xxx.archive: this can be nearly everything....

These archives can be decompressed with Sparkplug 2.23
(archivers/splug.sfx).

* Other archive types:
xxx.Z: compress
xxx.gz: GNU-Zip (gzip)
xxx.tar: tar

Look in the directory "archivers" for the corresponding cruncher.

* Text files:
xxx.txt, xxx.info, README

If a file doesn't have an extender, it is either a text file or an
unrecognized archive (those archives should disappear as soon as I
have some time for this :)

* Some files are neither text files nor archives. Those files have a
special extender which tells you what type it is (e.g. xyz.absolute is
a RiscOS executable). 

Please note that most README's don't use the extenders in the
descriptions!