The standard keycaps shipped with the Keyboardio Atreus are black, laser-engraved keys in the XDA profile. They're made out of PBT, a high-quality plastic beloved by keyboard enthusiasts for their resilience. The standard F and J keys installed on the keyboard include homing bars, but we also include extra F and J keys without homing bars with each Atreus.

The firmware powering all our keyboards, Kaleidoscope, is open source and freely available on Github. If you want to build complex macros, add in joystick emulation, change how the Atreus speaks USB, or make keys do things we haven't thought of yet, Kaleidoscope is where you'd start.

Kaleidoscope is incredibly powerful, but we've done our best to make it newbie-friendly. We built it on top of the Arduino core, to make it easy for folks who aren't familiar with embedded development or C++ to be able to do amazing things. At the same time, you're not restricted to the Arduino IDE when working with it. If vi or Emacs is your weapon of choice, everything's set up to build from the command line using standard tooling.

Kaleidoscope supports all the things you'd expect, like layouts stored in EEPROM, serial communications, full NKRO, mousekeys, and crazy USB tricks. Most new features can be added to Kaleidoscope as plugins, of which we have many already. 

QMK, another popular open-source keyboard firmware also fully supports the Keyboardio Atreus.

Unless you're buying the 'barebones' model which comes with neither switches nor keycaps, your atreus comes fully assembled with your choice of several different kinds of switches.

All of our switches are made by Kailh, one of the best switch makers in the world. Kailh rates all of these switches for at least 70 million keypresses. 

The Keyboardio Atreus features hot-swap sockets designed to let you remove the switches with a standard keyswitch puller (not included) and replace them with just about any MX-style switch, no soldering or disassembly required.

Very. At just 24.3 x 10 x 2.8cm (9.6 x 3.9 x 1.1 inches), it's easy to bring your keyboard with you everywhere.  

To get a better sense of just how compact the Keyboardio Atreus is, you can print out this PDF:

Downloadable papercraft Keyboardio Atreus

(Make sure your computer is set to print things at actual size, rather than shrinking or stretching them to fit on a sheet of paper. It should fit on a standard sheet of A4 or letter / 8.5"x11" paper.)

Thanks to its customizable layout and layers (that work just like your laptop's "function" key, but better), the Atreus can fit far more than 104 keys of functionality in to just 44 keys. Read an introduction to the Atreus layout.