Jacob Barton has only begun thinking about flamboyant microtonal blogging.
Kyle Gann: JI composer, musicologist, critic, teacher, provocateur.
Kraig Grady JI Composer, Instrument Designer and Builder, Archivist, Shadow Puppeteer
Harmonic Ratio: This blog is about a project to create computer software (and, potentially, dedicated interface harware) to facilitate the composition and performance of music based on integer ratios of frequencies.
Hπ Instruments Edutainment: Aaron Hunt's H-pi-related blog, with Tonal Plexus videos etc.
Jim Plamondon blogs about the ongoing innovations surrounding the Thummer (microtonal) keyboards.
Prent Rodgers has new "podcast bumper music" more often than not, thanks to his undying commitment to composing at least 10 minutes every 24 hours.
Daniel Thompson, self-described microtonal composer, links to videos and other yummy resources as well as original compositions.
Carlo Serafini Italian composer and microtonal experimenter.
Charles Loli Peruvian composer and microtonal experimenter.
Overtone Network Blog - as the name says, about overtone music
Music & Techniques by Chris Vaisvil Microtonal music and techniques used to realize it. Some 12 EDO stuff as well.
Ratio to SenseSitarist John Stephens' blog about harmonic theory and the practice of tuning.
Sevish Music Blog composer and microtonal experimenter. The blog has some tutorials and thoughts about electronic microtonal music.