Yes, Exponent CMS is still alive and being updated. Though development has taken a much slower pace, bugs are still being squashed and new features are being added. You can expect v2.5.1 to be released by the end of winter 2020 (March). This is actually a minor patch update to v2.5.0patch2, but due to the copyright being updated to 2020 it affects almost every file and would be a very large patch, therefore it'll be a full version release.
What are some changes can you expect from Exponent CMS in 2020?
- Become PHP v7.4 compliant...Exponent v2.5.1 will not be fully PHP v7.4 compliant and may not even run under a server using that version of PHP
- Attempt to integrate Twitter Bootstrap 5 when released. There is no date set for its release, but when integrated will likely move the Exponent version to 3.0.x.
- Remove PHP v5.6, v7.0 and v7.1 compatibility. Many 3rd party libraries no longer work under these obsolete (unsupported and no longer updated) PHP versions.
- Become MySQL v5.7 'Strict' Mode compliant. Exponent currently requires turning the default 'strict' mode of MySQL v5.7.x off or Exponent will NOT be able to create ANY new objects such as modules, items, or users. Some web providers will not modify their MySQL settings to allow this. This will be a pretty labor intensive code update and may require overhauling much of the code. Therefore it may be as easy to move to a PDO database interface.
Exponent CMS Developer