IDE

I built a lightweight code editor from scratch in Python/PyQt6, with a real extension system: extensions are just Python files that expose an activate(api) function, and the API lets them register commands, add toolbar buttons, hook into file-open events, and print to the built-in terminal. I also built a Marketplace panel that reads a JSON catalog and installs extensions into the app with one click.

The hardest part was debugging an environment issue that had nothing to do with my code — Windows Smart App Control was silently blocking PyQt6's native Qt DLLs from loading because they aren't signed with a certificate Microsoft's reputation service recognizes. Traced it through the Korean-language error message down to the exact Windows security policy before I could even get the app running again.

I'm proud of the extension API design — it's small (four methods) but already enough to let a sample extension add its own button and command without touching core app code.

To test it: clone the repo, pip install PyQt6, run python main.py. Click "Extensions" to open the Marketplace and install the sample extension, then use the toolbar button it adds. You can also open/edit files from the sidebar and run code directly with the ▶ button.