ArcFS

ArcFS 2 is the only free compression filing system (see image filing system) available for RISC OS. It was written by Mark Smith. While SparkFS can do everything either version of ArcFS does, SparkFS is commercial product. The free 'promotional' version of Spark and SparkFS is SparkPlug, which is not a filing system.

Restrictions (paraphrased from the ArcFS 2 Licence file):
 * 1) Copies of ArcFS 2 (Read only) may be passed between private individuals as long as this is done free of charge.
 * 2) ArcFS may be distributed by public domain libraries, as long as no more than &pound;5.00 is charged for a disk. If charges are higher than this, then the author's permission must be obtained first.
 * 3) It may be freely distributed on the Internet, as long as no charge is made for downloading it.
 * 4) ArcFS must not be distributed with software, other than as detailed above, without the author's permission. If a profit is being made from the software, permission will normally be granted in return for a small royalty or one-off payment.
 * 5) The copyright remains Mark Smith's at all times.