:bwbasic:bw32
The most current version of bwBASIC as of 2023 seems to be a strong diversion from 2.20 and previous versions, aimed at making the most for supporting a LOT of classic, especially mainframe and time-sharing BASIC dialects.
Some of these are cbasic, DEC BASIC-PLUS for RSTS-11 and for PDP-8 and PDP-11, the original Dartmouth BASIC, TRS-80 BASICs of its various levels, Microsoft MBASIC for Xenix and many others. Even the previous 2.20 version is emulated as a dialect, as "bywater2".
This emulation is not always precise and faithful, however. Some arbitrary design choices are made by its maintainers, and it seems that emulation emphasis is on supporting the keywords those BASICs had, while not so much on structural and syntactical oddities.
Dialects and an incredible number of syntatic and "behavioural" OPTIONs are implemented by bwBASIC 3.20 and might allow the user to create its own "emulation" of particular dialects.
As one might expect, the number of implemented keywords for all these dialects skyrocketed. But for the purposes of this site, the keywords considered are only those that bwBASIC 3.20 implements as its own "bywater3" dialect.