A comparison of tradeoffs using various web technologies should probably be a FAQ and updated once a year. The web is important, and unlike ruby and rails (or python and django?), there is really not one recommended dominating web framework in perl to start with.

I am going to start this post with what I understand.

• CGI.pm was a simple low- or mid-level framework. It has been deprecated. It is still supported for existing projects, but no one should start a new web project with it.
• PSGI/Plack is expressly middleware. While powerful and stable, it really is not designed for writing websites, but designed for use in higher-level frameworks. The authors are not too happy with (or equipped to) handle large number of noobie requests on how to use it, and the examples in the documentation are modest.
• The two primary choices for new modest-size websites are Dancer2 and Mojolicious. They have good documentation and are suitable for newbies. (Both frameworks are or can be users of PSGI/Plack, but this is transparent to the user programmer.) They are good high-level, but not stable. In particular, I know that Mojolicious is evolving---projects can break upon M updates. I don't know about Dancer2.
• For large projects, Catalyst becomes a third alternative.

So, for someone new who wants to learn how to code a website, there seem to be two primary perl choices. If my reading of the landscape is not correct, then please correct it. And if someone could please post the pros and cons of Dancer2 and Mojolicious---so that one does not have to learn both first to start with one---it would be helpful.

Personal Observation: What I liked about CGI.pm and Plack/PSGI over the frameworks was that lower-level code makes it easier to determine what perl code was responsible for displaying a given web page. With the frameworks, by the time all routes, templates, injections, etc., are considered, it becomes hard to trace how the given web page has been built. Where web programs are one's primary responsibility and used every day for years, the linkage within the frameworks is not a problem. One remembers instantly what was where. Where web programs are occasional tasks, separated by long periods of neglect, this becomes more difficult.

thanks in advance to the experts for illuminating the issues.