Communities developing resources and competencies for using their languages
Foundational understanding for language development work of all kinds
Publications, fonts and computer tools for language development, translation and research
SIL offers training in disciplines relevant to sustainable language development.
7,097 languages are spoken or signed. CLICK for map of world languages & regional websites.
SIL's dedication to language development past and present
Some other resources in the Areas pages also include something on tone, but these have tone as their main subject.
Also see the page on Fonts and technical issues, which discusses issues of grammatical tone marking and Unicode.