Musical notation

Notations that have been or could be used for composing/performing xenharmonic music

Circle-of-fifths notation (and neutral circle-of-fifths notation)
Ups and downs notation (and neutral ups and downs notation (with an alternative symbol set))
Syntonic-rastmic subchroma notation
Easley Blackwood's symbols for ETs 13-24
Mason Green's New Common Practice Notation
Tartini/Couper for 31edo
Julian Carrillo's index notation
Armodue theory for 16edo and other edos that deals with the superdiatonic scale (LLLsLLLLs) (notation of numbers [from 1 ~ 9] and accidental symbols).
The Pentadecaphonic System^{[dead link]} (adding the 'H' note)
David S. Goldsmith's notation for 16edo
H-System for 205edo
Maneri-Sims notation, Richter Herf / Maedel for 72edo
Wyschnegradsky color notation for 72edo
Heptatonic notation
Bohlen-Pierce theory for 13edt and other EDTs that deals with the nonatonic scale (LsLsLsLss) (adding "H" and "J" notes)
Erv Wilson's Linear Notations

See dedicated Scores page.

Ted Mook's font for notating Ezra Sims' 72-EDO notation et al. http://www.mindspring.com/~tmook/micro.html^{[dead link]}
Tempera font by Christian Textier - does anyone use these crazy things? http://pros.orange.fr/christian.texier/mididesi/^{[dead link]}
Matthew Hindson offers this font with quartertones and the like. http://www.hindson.com.au/wordpress/index.php/free-fonts-available-for-download/
Plainsound Music Edition fonts for the Extended Helmholtz-Ellis JI Pitch Notation (HEJI) - under "JI/MICROTONAL RESOURCES". https://www.plainsound.org/

Please see the list at page Software #Notation software