Speeduino, rusEFI, epicEFI, MegaSquirt
Published definitions load unmodified.
All four go through the same spec parser. The test suite loads real published INI files from each and must parse them without edits.
No per-firmware parsers
Behaviour comes from what the INI declares, not which firmware it is, so a new firmware release loads without a code change.
Test fixtures
Speeduino; rusEFI (several builds, including uaefi); epicEFI (epicECU, MS43); MegaSquirt Mini MS3.
Strict parsing
Ambiguous syntax is an error. Unambiguous typos, such as a missing comma, are recovered with a line-numbered warning.