The original COCOMO is introduced in Dr. Barry Boehm's textbook Software Engineering Economics. This model is now generally called "COCOMO 81".
Costar 1.0 is released.
Ada COCOMO and Incremental COCOMO are introduced (proceedings, Third COCOMO Users Group Meeting, Software Engineering Institute).
Refinements are made to Ada COCOMO.
Costar 2.0 is released.
Costar 3.0 is released.
Costar 4.0 is released.
Early papers describing COCOMO 2 published.
The first calibration of COCOMO II is released by Dr. Boehm, and named "COCOMO II.1997".
Costar 5.0 is released, supporting COCOMO II.
The second calibration of COCOMO II is released. It's named "COCOMO II.1998".
COCOMO II.1998 is renamed to COCOMO II.1999 and then to COCOMO II.2000 (all three models are identical).
The book Software Cost Estimation with COCOMO II (Dr. Barry Boehm, et al) is published to document how to apply the latest estimation model. Most of the original Software Engineering Economics is still applicable to modern software projects.
Costar 6.0 is released, and supports COCOMO II.2000, MBASE, REVIC, and schedule constraints.
Costar 7.0 is released, and supports drag & drop, wizards, XP, import from USC tool, toolbars, and filters.
SystemStar 1.0 is released, supporting COSYSMO 1.0.
SystemStar 2.0 is released, and supports the initial COSYSMO reuse model.
SystemStar 3.0 is released, supporting COSYSMO 2.0 and the COCOMO models. Also implements Monte Carlo sizing.