Excuse me if this is a "sparse" question but, I'm somehow confused wit the terms of "Undocumented API call" and "Toolchain" (of Saurik).
Are they same? Or toolchain is "yet another wrapper" for Undoc. APIs? Or entirely different things?
And what place does Erica Sadun's work sit in these definitions?
As far as I remember, "toolchain" refers to the unofficial iphone sdk and compiling tools, the ones you use to code applications that typically run on jailbroken iphones.
About Erica Sadun's work, I don't think there is a general answer as she published applications for toolchain but her book targets the official sdk.