As you know, migrating to Firebird 5 is one of the easiest ways to gain better performance and access many new features with minimal effort.
We recently received migration statistics from the Migration Framework (a service for automatic Firebird migrations, available in the Firebird Shop).
A few comments:
first, these statistics are only from the Migration Framework and do not reflect the overall number of Firebird 5 migrations.
Second, there is currently no reason to migrate to 3.0 or 4.0, since 5.0 offers the best compatibility and the migration difficulty is the same.
Third, firebirdsql.org download statistics show that Firebird 2.5, which was retired in 2019, is still being actively downloaded, meaning many developers are still using outdated versions of Firebird.
Are you still on an old version of Firebird?
If so, read the free migration guide to Firebird 5, watch the videos about migration: episode 1, episode 2, episode 3, episode 4, and see video about practical examples of Firebird migrations.
If you are not sure why you should migrate to Firebird 5, read the book "Detailed New Features of Firebird 5".