After a while I stumbled upon scsh [1], which at first didn't impress me because I ran it as an interactive shell, and from this point of view it was really ugly. But then I realized that scsh was primarily meant as a way to run shell scripts, and I immediately felt in love. I had the power of a Scheme interpreter, the ability to easily use mathematical expressions (the awesomeness of Scheme's numerical tower!) and macros, and a very effective way to redirect inputs and outputs and pipe commands that was embedded in the language [2]!
In those years I used scsh a lot and developed quite complex scripts using it, it was really a godsend. Unfortunately the program got abandoned around 2006 because it was not trivial to add support for 64-bit architectures. However, while writing this post I've just discovered that somebody has revived the project and enabled 64-bit compilation [3]. I would love to see a revamp! Nowadays I use Python for complex scripts, but it's not the same as a language with native support for redirection and pipes!