- Madekankomi by Flush (47 features)
- Magralgarlu by Yalgarpiril (22 features)
- Maja by Matrix (141 features)
- Majlang by aarginost (143 features)
- Makadian by Me (4 features)
- Makronesian by Aziz Bastosun (4 features)
- Maksinaunminverbe by Andrew Nelson (126 features)
- Mala by Catherine B. Krause (5 features)
- Malabas by Bipapo (101 features)
- Maltcegj by BenJamin P. Johnson (60 features)
- Mamambam by Creyeditor (54 features)
- Manchu by the Jurchen-Manchu people, and kuroda posted informations here (122 features)
- Mandalorian by Karen Traviss (74 features)
- Mane Injsikut by Mike Yams (16 features)
- Manspikin by Catherine B. Krause (0 features)
- Maqacho by Brv (50 features)
- Marag by clawgrip (56 features)
- Maraxxian by Jasper van der Horst (7 features)
- Marijo by Jon (95 features)
- Masculine Aniszunian Essebian by Becca (1 feature)
- Mashilhath by Vedertesu (43 features)
- Massalian by Skynamir (145 features)
- Matanin by Benjamin McAvoy-Bickford (34 features)
- matorian by capnodulia (81 features)
- Mavakhalan by Zhen Lin (114 features)
- Mayato MKII by k1234567890y (128 features)
- Medefaidrin by multiple authors (0 features)
- Meditsrai by chrisdb_notts (139 features)
- Medoson by - (0 features)
- Medusaean by ZMoring (22 features)
- Meftla by Serafín (143 features)
- Meino by Jeffrey Daniel Rollin-Jones (145 features)
- Mekavant by Becci Cat (0 features)
- Mekoshan by Taylor Selseth (142 features)
- mekxetxe by Tapeworm (0 features)
- Meletsian by iewi (41 features)
- Melfem by Josh Regev (51 features)
- Menxháo by Alex Sanchis (81 features)
- merechi by Amanda Furrow (23 features)
- Mesak by Adarain (90 features)
- Mesodian by Andres Rincon (0 features)
- Mezhat by Miles (95 features)
- Miapimoquitch by Dirk Elzinga (85 features)
- Middle Olgish by Michael M. Goessler (69 features)
- Miirna by Kenneth Nyman (77 features)
- Mikiana by Rebecca Bettencourt (79 features)
- Mikoshi by Michael M. Goessler (54 features)
- Mila by Gary Taylor-Raebel (0 features)
- Milevian by Nick Brands (0 features)
- Millennish by Dillon Hartwig (143 features)
- Mindakri by Rebecca Ashling (121 features)
- Minhast by Kirmek (C. Borillo) (141 features)
- Mini by S.C. Gruget (109 features)
- Minza by Herman Miller (141 features)
- Mipukwi by Jonah Gleason (50 features)
- Mira by druneragarsh (89 features)
- Mirexu by Amanda Furrow (15 features)
- Miri by Nate Penner (19 features)
- Mîrkšam by Strahinja Ćirić (140 features)
- Missa by sodarayag (144 features)
- Mithara by Micamo (143 features)
- Miut by Sorajima Asugawa (38 features)
- Miwonsha by Plusquamperfekt (54 features)
- Mli Vjacgu by Amanda Furrow (35 features)
- Modern Arithide by Eugene Oh (136 features)
- Modern Eltan by worldofcrazies (114 features)
- Modern low Ponuhi by Creyeditor (77 features)
- Modified Basic E-Prime by j. jambec (5 features)
- mollydot's first go by mollydot (langfafflr) (17 features)
- Mondlango by He Yafu (132 features)
- Moniranian by Monir (12 features)
- Morlandian by Bryony (80 features)
- Moten by Christophe Grandsire-Koevoets (139 features)
- MPCL(PN) by Rhebeqah (49 features)
- Mugini by Colz (19 features)
- mundeze by Djuna de Lannoy (87 features)
- Mungitol by Timmytiptoe (11 features)
- Muosan by Ali Ghozali (54 features)
- Muosanese by ali (19 features)
- Myonian by Lyhoko Leaci (72 features)
- Myrsani by A. Klein (19 features)