- Leaflet -
34.23k- http://leafletjs.com/download.html - Esri Leaflet
47.15k- https://github.com/Esri/esri-leaflet/blob/master/dist/esri-leaflet.js - Mapbox
58.64k- http://www.mapbox.com/mapbox.js/api/v1.3.1/ - OpenLayers 3
85.53k- http://ol3js.org/ - CartoDB
150.25k- http://developers.cartodb.com/documentation/cartodb-js.html#sec-1 - OpenLayers 2
187.78k- http://openlayers.org/api/OpenLayers.js - Esri Compact
204.54k(no Dijit theme) - http://js.arcgis.com/3.6compact/ - Esri Standard
325.43k(Claro Dijit theme)- http://js.arcgis.com/3.6/
The command I used to estimate the size once gzipped is gzip -c filename.min.js | wc -c. Every library except open layers includes it CSS in the total size. Esri Standard includes the Claro widget theme but compact does not.
Is it out of beta yet?