Terminal Shell Tools
A shell is the program that reads what you type, runs it and hands back the result. It is an interactive prompt and a scripting language in one, a design that dates to the Bourne shell in 1979.
Most systems ship with Bash or Zsh. Alternatives change the defaults: fish adds autosuggestions and syntax highlighting out of the box, Nushell and Elvish move structured data through pipes instead of raw text, and Xonsh mixes Python into the command line. Several keep POSIX compatibility so existing scripts still run.
Below is a list of terminal shells.

atuin
Sync, search and backup shell history.
Sync, search and backup shell history.

flyline
Modern command-line editing for bash.
Modern command-line editing for bash.

hishtory
Your shell history: synced, queryable, and in context.
Your shell history: synced, queryable, and in context.

hstr
A bash and zsh shell history suggestion box for your command history.
A bash and zsh shell history suggestion box for your command history.

intelli-shell
Like IntelliSense, but for shells!
Like IntelliSense, but for shells!

omp-manager
A TUI that sets up Oh My Posh from scratch.
A TUI that sets up Oh My Posh from scratch.

rura
An Interactive TUI scratchpad for building shell pipelines.
An Interactive TUI scratchpad for building shell pipelines.

shellcheck
A static analysis tool for shell scripts.
A static analysis tool for shell scripts.

x-cmd
A compact swiss army knife for the terminal.
A compact swiss army knife for the terminal.
Know any terminal tools that would be good for this list? Post a Tool here!