Irijule is a San Francisco–based consumer electronics company founded by Evan Swanson and Scott O'Hair, best known for developing the TheoryBoard (Thy333), a MIDI controller built around the structure of music theory. Rather than laying out keys chromatically, the TheoryBoard splits its surface into chord pads on one side and single-note pads on the other, with both halves mapped to whichever scale the player selects.

The Thy333 features 93 velocity-sensitive RGB pads, an illuminated LCD display, and connects over MIDI, USB, and Bluetooth. It ships with a library of over 860 scales drawn from a range of cultures and genres, positioning it toward producers, beatmakers, and educators who want fast access to diatonic chords and melodic material without reading staff notation. The product was originally funded through a Kickstarter campaign that exceeded its goal within weeks.

Irijule operates as a single-product company centered on the TheoryBoard platform, selling direct through its website and through retailers including Reverb, Guitar Center, and Musician's Friend.

Irijule has 1 product cataloged on Equipboard, including MIDI Pad Controllers.