2 - High-level what is PSGI:
3 - Interface between web app and web server.
4 - a specification (not code)
6 - Why care about understanding PSGI when you can just use a high-level language.
8 - Alternatives: CGI, mod_perl, FCGI, SCGI, WSGI (Python), JSGI (JS), Rack (Ruby), ISAPI (IIS)
10 - Describe how CGI, mod_perl, and FCGI work.
12 PSGI is easy. RFC 3875 (CGI 1.1) is 36 pages.
13 The PSGI spec is shorter and much more consumable.
19 - Alternatives: Paste (Python),
20 - Rack-compliant: Rack (Ruby), Clack (Common Lisp)
23 - Web frameworks only need to target PSGI.
24 - Easy to write tests because requests and responses are data, not necessarily bytestreams.
26 - What frameworks support PSGI?
27 - [Catalyst](http://www.catalystframework.org/)
28 - [Mojolicious](http://mojolicious.org/)
29 - [Dancer](http://perldancer.org/)
30 - [CGI::Ex](https://github.com/chazmcgarvey/CGI-Ex/tree/psgi-2)
32 - What handlers does plack support?
34 - What types of things should be written as middleware?