Arundina fonts [0] were created under SIPA's initiation, aiming at Bitstream
Vera [1] / Dejavu [2] compatibility. They were then further modified by TLWG
for certain aspects:

  * Latin glyph size compatiblity. That is, Latin glyphs should have equal
    size with those from Western fonts at the same point size, so that it
    would not require users to scale fonts when using them together in the
    same documents.

  * OpenType conformance. We attempt to fullfill OpenType requirements for
    Thai fonts[3], according to our drafted spec [4]. However, as many
    applications, including MacOS before Leopard and Adobe CS2, do not support
    the Thai-specific features well, the 'liga' GSUB hack developed by the
    original author is still retained for the time being.

We use FontForge as development tool. You need it to generate fonts from the
downloaded source.

For more information, see our project page at:
  https://linux.thai.net/projects/fonts-sipa-arundina

Links:
[0] https://www.f0nt.com/release/arundina-by-sipa/
[1] https://www.gnome.org/fonts/
[2] https://dejavu-fonts.github.io/
[3] https://docs.microsoft.com/en-us/typography/script-development/thai
[4] https://linux.thai.net/~thep/th-otf/