I ran across the MS Wish List website the other day while searching for more agents to query. It looks like a great resource. An author can select a genre and see a list of agents/editors/pubishers who are interested in that genre. And, the genre selections are numerous. After choosing a few candidate agents, I poked around a bit more on the site.
From what I can tell, this site is a filter for various Twitter hashtags related to agents/editors/publishers. The one I used to select agents by genre was #MSWL. A selection menu along the top chooses other hashtags, such as #AskAgent, #Querytip and #Pubtip, and various hashtags giving reasons why queries are accepted or rejected. I'm not sure how it all works, but I suspect the agents, etc. register on the site and then their hashtagged tweets are snagged and displayed in the proper category.
One disconcerting thing is the tweets come with no context, especially the query tweets. It gets confusing. I suppose you have to navigate to the original tweeter site to see more. Another thing: looking at the tweets shows lots of other interesting hashtags related to writing and querying (#amwriting, #amreading, #amquerying, #QueryMe).
One exciting thing I saw on the raw #MSWL Twitter site was that February 8, 2017 was proclaimed as "MSWL Day" on the site. I gather it means agents/editors/publishers were tweeting like mad what they're looking for. I was quite interested to see what it looked like, and found several leads for sending out queries. I also saw trends that I need to keep in mind for future projects, such as women protagonists or characters/heroes from "underrepresented groups."