From the project website:<p>> Yash is intended to be the most POSIX-compliant shell in the world while supporting features for daily interactive and scripting use. Notable features are:<p><pre><code> * Global aliases
* Arrays
* Socket redirection, pipeline redirection, and process redirection
* Brace expansion and extended globbing
* Fractional numbers in arithmetic expansion
* Prompt command and command-not-found handler
* Command line completion with predefined completion scripts for more than 100 commands
* Command line prediction based on command history
</code></pre>
I'm particularly taken with it's support for configuring the relevant keyboard
commands, with strong support for both Emacs and Vi bindings.<p>It also uses much less RAM than many other shells with similar interactive features, to the extent that matters to folks these days.