Mwmbl is the first search engine to allow users to change the search results:
You can add results, delete them, and rerank them. The changes you made are saved instantly to the index and will be shown to other users who run the same query.
But what is the point of users changing search results? There are far too many queries to expect them all to be curated by users.
The answer is that we can learn from users’ curations. For example, we can learn which sites are generally ranked higher than others, for example if MDN is ranked above w3schools. More generally, we can use machine learning to rank results, with curated searches as a training set. This is called learning to rank.
By curating search results, you are really training Mwmbl in how we should rank pages.
There are still a lot of things to figure out, most importantly, how do we define what is a good ranking, and how do we reach consensus around a ranking?
At the moment, one person can change the results for everyone instantly, following the model of Wikipedia. But perhaps we will need some kind of voting system to make it easier to resolve disagreements, perhaps with upvoting and downvoting like StackOverflow.
The important thing though, is that the community determines the ranking. In commercial search engines, the ranking is determined by what will make the search engine the most money (and of course, normally includes advertising). As a non-profit, we don’t have that constraint, so we can provide a better service to users. Well, that’s the theory, anyway!