My example was from shell string interpolation/`sh`, which predates TCL by more than a decade. Not sure where your "I'd like people to study PL design history"

My example was from shell string interpolation/`sh`, which predates TCL by more than a decade. Not sure where your "I'd like people to study PL design history" comes from. It sounds kind of pretentious tbh. We were looking for popular languages that use a syntax similar to `\{x}` for string interpolation. TCL uses a dollar sign, so pretty much as far from the C# syntax as possible (inside of the limited syntactical range out there). At least this page does not list any language that uses the same syntax: http://rosettacode.org/wiki/String_interpolation_%28included%29 http://rosettacode.org/wiki/String_interpolation_%28included.... But maybe your vast knowledge of PL design history can provide information on one that does?