http://art-of-small-steps.blogspot.ie/2017/11/logging-in-programming-contests.html

TL;DR example is here https://gist.github.com/metaflow/87d7df206e1e0a9fa9eb8a5dc4ac6bea

I have noticed that format of Problem in API response has changed: now tags is not a list of strings but json objects. E.g.: http://codeforces.com/api/contest.standings?contestId=800

Could admins please update docs to reflect that?

I have noticed that old contests sometimes have a very abbreviated editorial (if any) with proofs omitted or just an author's solution without description. I think it would be nice to have a way to the community to step in and provide / improve existing editorials. For example by having wiki pages or allowing linking user's post to an existing problem (without beeing original problem setter or admin). Of course, that may lead to all problems with abuse but people here are way more reasonable than an ordinary forum.

What do you think? Maybe that already exists and I am missing something?

If you read editorial after solving one of the archived problems and don't want to spoil unsolved ones, you might find this custom javascript extension snippet useful:

$(function() {
if ($("a.tag:contains('editorial'),a.tag:contains('tutorial')").length === 0) return;
$(".content h2, .content h3").each(function(a,b) {
  var <span class="tex-span"><i>h</i> = </span>(b);
  var $t = $h.nextUntil('h2, h3');
  $h.after("<a href='#' class='show-spoiler'>show</a>");
  var $l = $h.next('.show-spoiler');
  $l.click(function() {
    $t.css('visibility', 'visible');
    $l.remove();
    return false;
  });
  $t.css('visibility', 'hidden');
});
})

I have not tested it on each and every editorial ^_^ upd1: fixed issue with picking 'editorial' links from new's block