The kickstarter page seems to assume I know what xiki is and why it's different from say bash.
There's overlap with IPython notebooks. There's command-aware autocompletion. There's direct-two-way-manipulation of textual artifacts.
Maybe it could be thought of as an "MVC" IDE, but in pure-text, where familiar Unixy commands can be the "VC" parts... and you don't so much "run" them once but position them for re-use, and their output can be made directly editable with effects on the original inputs. (As just one example, what if editing the output of "ls -l" was enough to change permission bits, owners, or names of files, or truncate them to a new length?)
It even reminds me a little of the Englebart "Mother of all Demos", in the surprising/dangerous depth behind simple outline-menus.
Note I'm just assessing from the videos: I haven't used Xiki myself. If I were using it, I think I might handle it like a loaded weapon: it seems powerful enough to do a lot of filesystem damage in a few experimental keystrokes!