[zarzavat]

Jawi is basically Arabic script it just has a few extra glyphs to handle phonemes that don't exist in standard Arabic. For example /p/ or /ng/ (velar nasal).

Anybody who can read the Quran and speak Malay can also read Jawi with minimal effort, which is most of population of the Malay archipelago.

A similar but distinct script was used for languages of Indonesia, e.g. Javanese and Sundanese.

[jfk13]

That would be Pegon, https://en.wikipedia.org/wiki/Pegon_script.

However, both Javanese and Sundanese also have their own distinct writing systems that are not based on Arabic (https://en.wikipedia.org/wiki/Javanese_script, https://en.wikipedia.org/wiki/Sundanese_script) and would not be at all readable to an Arabic reader.