By Dan Vanderkam, based on lmnopuz, by Evan Martin and Dan Erat

Puzzle+ is a crossword puzzle application for Google+ Hangouts. It allows collaborative solving of crosswords (i.e. puz files) in G+. The hangout provides videoconferencing to go along with the puzzle-solving.

Visit its home page to start a Hangout with Puzzle+ enabled.

To run locally, you'll need to install node.js. Then run:

git clone https://github.com/puzzleplus/puzzleplus.git
cd puzzleplus
npm install
./node_modules/.bin/lonely app/puzzleplus.xml

And visit localhost:8080 in your browser of choice. At this point, you have a standard save-reload iteration cycle.

You can open localhost:8080 in multiple tabs (or multiple browsers) to test multiplayer situations.

This uses lonely hangouts to simulate the Google+ Hangouts API.

All state in a Hangouts app is contained in the global, shared state object. For Puzzle+, the state object looks like this:

{
  "crossword": "...",         // (bytes of the .puz file)
  "@rgb(178,255,178)": 1234,  // @ + color -> player ID
  "c1234": "4,2",             // c + player ID -> cursor position
  "1,2":"O\t1234",            // (x, y) -> "Answer<tab>Player ID"
  "2,2":"R\t1234",
  "3,2":"T\t1234",
  ...,
  "g1,1,x": "",  // wrong guesses
  "g3,4,y": "",
  ...,
  "v,check,(type),(player_id)": "",  // pending votes
  ...
}

If some of the mapping seem a bit strange, it's because the state object is structured to take advantage of the Hangout API's conflict resolution system. For example, rather than mapping player ID→color, it maps color→player ID. This means that the Hangouts server will ensure that no two players ever have the same color.

To publish an update to "production", run:

cp app/* ../puzzleplus.github.io/app/

And then push the changes to puzzleplus.github.io.

The Google API project, which contains branding information and a pointer to the XML file, is called "puzzle+".

2007-2008

derat and emartin create lmnopuz, with a JS frontend and a Ruby backend. The service works, but there's no good place to host it.

2009

After learning about Wave, danvk remembers lmnopuz and writes the code to store crossword state in a wave. Work is abandoned after the realization that there's no way to access uploaded files via JavaScript, a crucial feature of lmnowave.

2010

After going on a hike with another developer, danvk learns that Firefox 3.6 has added support for the HTML5 File API. lmnowave is now possible! Hacking resumes!

2011

Wave is canceled, but the Wave Gadgets API (and hence "lmnowave") lives on as "Google Shared Spaces".

2012

Google Shared Spaces is killed/morphed into the Google+ Hangouts API. lmnowave is rebranded as "puzzle+" and re-released. Lonely Hangouts is also developed and released to speed up iteration on multiplayer scenarios.