What are some alternatives?
When comparing Rush and DASH, you can also consider the following products
zsh - The Z shell (Zsh) is a Unix shell that can be used as an interactive login shell and as a powerful command interpreter for shell scripting.
fish - The friendly interactive shell.
Bitcoin - Bitcoin is an innovative payment network and a new kind of money.
rc - a shell - This is a reimplementation for Unix, by Byron Rakitzis, of the Plan 9 shell.
Litecoin - Litecoin is a peer-to-peer Internet currency that enables instant payments to anyone in the world.
the xonsh shell - Xonsh is a Python-powered, cross-platform, Unix-gazing shell language and command prompt.