Tantor SE-1С includes several procedural languages with the base distribution: PL/pgSQL, PL/Tcl, PL/Perl, and PL/Python.

In addition, there are a number of procedural languages that are developed and maintained outside the core Tantor SE-1С distribution. A list of procedural languages is maintained on the PostgreSQL wiki. Note that some of these projects are not released under the same license as Tantor SE-1С. For more information on each procedural language, including licensing information, refer to its website and documentation.

https://wiki.postgresql.org/wiki/PL_Matrix