The idea is to pick bits of zebra/quagga (the interactive tab-completion command-line based user interface), bits of SCEZ, write the intermediate code and link against pcsc-lite ;)
The result is an interactive tool for ISO 7816-4 based chipcards (aka smartcards) that anyone can use to explore such cards. Instead of putting together APDU's by yourself and entering hex code, you can specify easy commands such as "select file absolute fid 1234".
The cardshell core will support plugins for new commands and especially card-specific bits, so you can load a plugin for the specific card you're using.
At the moment I have implemented a couple of basic commands, but I'm lacking important features such as secure messaging. Stay tuned...
It's extremely surprising that up to now there is no such application around. How are people developing smartcard based applications? typing hex bytes by hand?