The best replacement for infowindow is infobubble.

The best alternatives to infowindow are rated as following:
★★★★★  infobubble
★★  infobox

Your alternative for infowindow is not listed? Suggest!
Speaking about infowindow, one probably shouldn't forget about marker.

Other search terms related to infowindow and their ratings are:
★★★★★ marker
You have in mind a companion for infowindow and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of infowindow in all years. Click on graph for more.
infowindow
infobubble
infobox