Septabee is a free DAW for Windows and Linux that arrived in early access this month. It is node-based, it has no third-party plugin support, and it runs on a programming language its developer wrote himself.
The developer goes by Lost Robot. He has since posted the full history of the project in his Discord, and that history is more interesting than the software’s reputation for being strange.
The first version dates to June 2021 and was called Woven Music Studio, named after a game he was making at the time. It was built in Code::Blocks and SFML. It was also his first C++ program.
“Back then I had absolutely no idea what I was doing,” he writes. “I had basically no knowledge whatsoever about CPU usage, realtime safety, or any other essential things for making a decent DAW.” He suspects it was hitting 100% CPU on the most basic projects.
He rewrote it from scratch on 15 April 2022. That version introduced an infinite panning workspace to get around limited screen space, and made almost everything modular, though parameters still could not be modulated.
The next rewrite came in July 2023 and brought infinite zooming with nested capsules, which he says became the core of the interface for every version since.
Then he kept going. By his own count the current Septabee is roughly version 9, started on 11 January 2026. His summary of the process: “TL;DR 9000000000000 program rewrites.”
One problem kept recurring. “I was always so focused on fleshing out its synthesis capabilities that the program wound up being a synth pretending to be a DAW.”
Performance was the real obstacle. Septabee’s design calls for unlimited oscillators, freely created feedback loops, and any module modulating any other at full audio rate, sample-accurate. That is expensive.
He says he spent thousands of hours becoming an expert in CPU optimisation and it still was not enough. “Such heavily modular synthesis with exclusively audio-rate modulation was simply too expensive to even be possible.”
The fix is the part worth understanding. Rather than running a modular engine, Septabee writes fresh code as you patch and compiles it in real time, using CPU instructions specific to your exact hardware.
“I realized that I could make this modular DAW have the same (actually better) performance as other DAWs, if I could generate C++ code on the fly and compile it in realtime to exactly emulate what that hypothetical modular synthesizer would do, but without truly being modular,” he writes. “That’s the main invention that drives Septabee to this day.”
The logic is straightforward once stated. A modular engine spends its life checking whether each connection is in use and whether each feature is active. Compiling the patch down to fixed code removes those checks entirely. B++, the language he built around this approach, is where it ended up.
He also built a temporal supersampling feature that emulates a higher framerate on a 60Hz monitor.
The nodes are called pomegranates. The keyboard shortcut is P, and also Z.
Stock modules cover Visualizer, Wavetable, SineDemo, SF2Player, Filter and Limiter. There is an infinite piano roll tunable to any scale, an SF2 player that handles microtonality, and support for hundreds of voices in monophonic or polyphonic arrangements.
There is no VST support. Nothing you already own will load. You build your own instruments and effects, or use ones other people share.
Lost Robot’s own label for this build is “violently unfinished.” James Nugent at Bedroom Producers Blog notes that the setup screen is headed “Septabee setup window thingamabob” and the settings box reads “I hope this works.”
Septabee is five years of one person failing and starting over. His claims about crash immunity and CPU performance cannot be verified, because the program is free but not open source. The work behind them is documented in unusual detail.
Producers who want something that opens and behaves predictably have better options, and both Audacity’s rebuild and Reason’s free rack arrived this month. Septabee is for people who want to build the instrument before they write the part.
Septabee is free and in early access, Windows and Linux only, with no macOS build. It is available from septabee.nekoweb.org, with a Discord community linked from the developer’s tutorial video.
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