Tcl 8 was just released, and yes we were using it, it hardly mattered that much.

Our product was inspired by AOLServer and Vignette, providing similar kind of capabilities, we had Rails in Tcl, but we were not a famous SV startup, rather mostly serving the Portuguese market.

The founders then went on to create OutSystems, built on top of .NET and Java, nowadays using other stacks, while offering the same kind of RAD tooling.