Documentation
These documents are relevant for implementing ACAP
Latest version ACAP 1.1 (September 2009)
ACAP 1.1 specifications, Part 1
ACAP 1.1 specifications, Part 2
ACAP 1.1 Implementation Guidelines
First version ACAP 1.0 (November 2007)
ACAP 1.0 specifications, Part 1
ACAP 1.0 specifications, Part 2
ACAP 1.0 Implementation Guidelines
You can download and use them all for free.