Software (File Formats Mostly)

1. _______ is the word used to describe the famous Russian dolls, or the "nested" dolls within dolls within dolls, to a certain number of iterations. It is also the name of a popular multimedia container file format that can hold several different files in one file. What?

2. The presentation software in Apple's iWork suite saves files with the extension '.key'. What is the full name of the file format/software (they're the same) and why are they called so?

3. Chicken is a free compiler for the Scheme programming language. It uses C as an intermediate language (that is, it first compiles Scheme code to standard C and then lets a C compiler compile it further). What are Chicken extensions commonly known as?

4. An EXE is a Windows executable file. What is an XEX?