Update: Tim Bunce also wrote a blog entry laying out his own vision for the recommendation mechanisms.
The periodic pressure point of CPAN having a plethora of modules with overlapping functionality and no real efficient way to choose between them (arguably, there is cpanratings) surfaced again. A long time ago, I drafted a possible recommendation system, and despite the time that passed, I still believe that I was unto something (which either hint at truly a worthwhile core idea, or deep delusion. Which one it is? Only time, and the blog comments, will tell.). But, y'know, time being scarce and all that, I let the whole thing go to sleep. Now, however, feels like a good time to take a deep breath, clench my teeth, jut my jaw forward and have another go at it.
The CPANvote mechanism, revisited
MetaCPAN, bless its magnificent little heart, took care of the voting part of things already. So we can ignore all the voting stuff from the old cpanvote and concentrate on the recommendation part. Which leave us with a very simple core feature:
Logged in MetaCPAN users should have the ability to recommend an alternative to any distribution.
Just like that. For example, I should be able to go to the Path::Class page and recommend Path::Tiny as an alternative. Nothing more, nothing less. And then the webpages of the various distribution would display the tally of their alternatives.
Sidenote: at first I was also considering the possibility to add a small note to the recommendation, but finally decided the (initial) system is probably best without. In part because simpler is better, but mostly for the political aspect of the thing. No matter how gently we do it, a recommendation system will always be a delicate affair. And in that optic, keeping things as spartan and neutral as possible is probably a good tactic. The same logic goes in the 'recommended alternative' nomenclature, which only says that the author recommends B over A, but without any overbearing implicit sense of conveyed superiority of one over the other.
Aaaanyway, that's my proposition. So, now, what needs to be done for it to happen? Three things.
First thing: Carve a space for the recommendations in the MetaCPAN backend
Basically, the MetaCPAN database needs to have a new list of recommendations (recommended dist + who made the recommendation ) attached to each distribution.
Should be easy to do. Current problem: I'm an Elasticsearch n00b, and don't have the keys to MetaCPAN's backstore. Current plan of attack: contact the MetaCPAN overlords, and lobby with the best puppy eyes I can muster.
Second Thing: Implement the front-end recommendation input
Basically, if you're logged in on MetaCPAN, a 'recommend alternative' button should be seen beside the '+1'. Click on the button, and a text input appears to enter the recommended distribution (bonus points for an auto-complete like the main MetaCPAN search input). Recommendation done triggers an ajax call that registers it to the backend (open question: should a recommendation automatically +1 the recommended dist?). Subsequent views by the user should have a modified 'recommend alternative' to make clear that they recommended something else (just like the '+1' looks different if you clicked on it).
Third Thing: Show the recommendations
On dist pages, probably above the 'Dependencies' widget on the right side, have a 'Recommended alternatives' of the format:
Acme::Bleach (Damian Conway and 6 others) Acme::EyeDrops (Andrew Savigne and 3 others) AAAAAAAAAA (Yanick Champoux)
Enough Talk, Let's Do It
Actually, we still need to talk. Amongst other things, I do have to check with the MetaCPAN folks if they agree with the plan. While I think they will, it is fully their right to shake their heads and go "oh sweet $diety, noooo...".
But assuming that they don't massively facepalm at the idea, and if you want to help, drop me a line. Things #2 and #3 are (fairly) straight-forward, and can easily be stubbed in without having #1 done. Just fork metacpan-web, and get cracking.