After several years of running it as a small commercial app, I’ve just open-sourced my desktop CSV editor Tablecruncher under the GPLv3 license. The full source code is now on GitHub, along with pre-built binaries (still beta for now) for macOS, Windows, and Linux.

Why I built it

It started as a personal learning project to explore C++ and FLTK, but turned into something real when I needed a fast, lightweight way to open huge CSVs on my Mac. Over time, it evolved into a full editor with a clean UI, keyboard shortcuts, dark mode, and more.

The surprising part? People actually bought it. I had paying users from more than 70 countries and lots of positive feedback from folks dealing with data—scientists, developers, journalists. That encouragement is what still makes this project fun for me today.

Why I’m open-sourcing it now

It started as a side project, and it always was a side project. To keep it alive as a side project, I realized the best path forward was to open source it. It lets me share the tool with others without dealing with the overhead of licensing, payments, or other commercial hurdles.

Plus, it feels good to give back. If this tool can help someone clean up a messy CSV file, that’s already a win.

Tech Stack

• Written in C++, with a minimal and fast GUI using FLTK

• Supports JavaScript-based macros, powered by the embedded Duktape engine

• Includes a custom CSV parser optimized for speed and large files

• The open source release drops Boost to simplify the build process and reduce external dependencies

• All dependencies support static linking, so binaries are self-contained with no runtime requirements

• If you like my hand-crafted icons, they're published under the CC BY 4.0 license 😉

Would love to hear your thoughts, especially if you're also working on small data tools or desktop apps.

Thanks!
Stefan