A body known as the IT Governance Institute (ITGI), and ISACA (Information Systems Audit and Control Association).
How often is it updated
Broadly speaking, about every 3 years.
When was it first published?
In the early nineties.
Why does everything with COBIT cost money?
Is there a software tool for implementing COBIT?
Oracle Financials is now COBIT-enabled.
Are there COBIT tools for MS-Project or MS-Visio?
What other authoritative tools relate to COBIT?
ValIT (Value from IT investments) relates to COBIT, comes from ISACA, and is targetted more at the information management roles responsibilities of the CEO, CFO, and business managers, not just "IT staff".