A security engineer built a personal tool after Excel became too slow and fragile beyond 300 rows. The standout feature is that project data never leaves your device. The tool enforces a
It works from a local file with no internet connection at all, and you can open your browser's developer tools to watch the network tab and confirm zero data leaves after the page loads. Feature-wise, it works like a spreadsheet grid linked to the chart: paste in rows, drag to reorder, and group tasks into a hierarchy. Task are set with simple text like "start 3 days after the task above finishes," and the tool automatically accounts for weekends and holidays.
Edits work both ways — double-click the chart to add a task, or type in the grid. There is no account, no login, no usage tracking, and the code is under the , meaning anyone can use or modify it for free.