Datum Bench is maintained by one person, so the fastest way to reach me is email rather than a contact form:

[email protected]

A few things that help me respond faster:

• Bug reports — which tool, which coordinate systems or units, and (if possible) a sample input file or value that reproduces the issue.
• New coordinate system requests — the EPSG code if you know it, or the country/authority that defines it, and roughly where it's used.
• Feature requests — what you're trying to accomplish, not just the feature itself; it helps prioritize what to build next.

I read every message, though replies can take a few days depending on my day job as a GIS Analyst. See the About page for background on who built this.