I’m a big F# lover. I really fell in love with the density and expressiveness of the language. Today I noticed the following blog post where Tomas Petricek wrote an Excel variant in about 100 lines of F# code. Truly impressive!
Go check out the blog post here; http://tomasp.net/blog/2018/write-your-own-excel/ and have a look at the completed code here; https://github.com/tpetricek/elmish-spreadsheet/tree/completed