Editing ACIS (section)

== Version Numbers and ACIS Releases ==
ACIS is currently being developed by Spatial.  They maintain the concept of a current version (release) number in ACIS, as well as a save version number. The save version allows one to create a SAT save file that can be read by a previous version of ACIS.

Beginning with ACIS Release 4.0, the SAT save file format did not change with minor releases, only with major releases. This allowed applications that are based upon the same major version of ACIS to exchange data without being concerned about the save version. To provide this interoperability in a simple implementation, ACIS save files have contained a symbol that accurately identified the major version number, but not the minor version. This meant that applications created using the same major version of ACIS would produce compatible save files, regardless of their minor versions. This was accomplished by simply not incrementing the internal minor version number between major versions.

Beginning with Release 7.0, ACIS started again providing accurate major, minor, and point version numbers. Beginning with Release 2016 1.0 in September, 2015, Spatial updated to Semantic Versioning, and now describes versions by the model year and major, minor and point releases within that model year.

To summarize how release numbers and SAT changes are related:
* '''Major release''': SAT file changes may be made; significant functionality changes likely; may require significant changes to existing applications
* '''Minor release''': No SAT file changes are made; may provide new functionality; may require some minimal changes to existing applications
* '''Point release''': Minor changes only (bug fixes). (Also known as service packs).

{|class="wikitable"
|-
! Release
! Date
|-
|2020 1.0
|2019.Nov.12
|-
|2019 1.0
|2018.Nov.13
|-
|2018 1.0
|2017.July.26
|-
| 2017 1.0
| July 2016
|-
| 2016 1.0
| September 2015
|-
| R25
| July 2014
|-
| R24
| June 2013
|-
| R23
| August 2012
|-
| R22
| July 2011
|-
| R21
| May 2010
|-
| R20
| May 2009
|-
| R19
| July 2008
|-
| R18
| November 2007
|-
| R17
| April 2007
|-
| R16
| January 2006
|-
|}