SIL serves language communities worldwide, building their capacity for sustainable language development, by means of research, translation, training and materials development.
One of the valuable resources offered by SIL are various computer fonts, such as the Doulos SIL font set.
You can download the the Doulos SIL font set from the SIL website.
There’s a maintenance release of the font for use with Firefox, but most people will use the official release.
Apple Mac computer users can expand/open the zip file, and then double-click on the font to have it installed using the Apple Font Book utility. Windows users can use a similar method to install the font. It is also compatible with Linux.