It's a completely new scripting language. It uses C-style braces rather than the more ALGOL-style `if / fi` keywords. However the core syntax of the language sh

It's a completely new scripting language. It uses C-style braces rather than the more ALGOL-style `if / fi` keywords. However the core syntax of the language should still be familiar to those who use Bash (eg pipes, commands, `$` sigils). So there is a little more to re-learn than you would with Fish but it shouldn't feel alien to read and write.