XTC is a variation on the Scope Project theme. The XTC board is the same exact board as the Scope Project board (originally called Pulsar 2) except it does not include the optional I/O attachment and cable whip. 

This product was originally designed to be installed alongside an existing soundcard in a system configured with Cubase or Nuendo or any recording/sequencing  program which incorporates Steinberg's VST plug-in standard. 

XTC provides additional high-quality Creamware effects that use the board's DSP resources instead of the host processor. This product fills a need for those who already have a high-quality recording sound card installed in their system but are looking to expand the range of usable effects of the recording application. Or... it could simply be used as a DSP "upgrade" in cases where you need additional DSP capacity for an existing Scope product, which is how we're using it here in our studio.

These days, Creamware refers to this product as Scope SRB (Sonic Rocket Booster). There are two Scope SRB versions: the 6 DSP card (shown above) and a 14 DSP card.