Tacticalendar is an innovative calendar design implemented in SVG. It always lets you see 4 weeks ahead, even at the end of the month, unlike ordinary month-view calendars. When a week has passed, the oldest week slides out of the top. All the other weeks slide up. The oldest week is erased, reconfigured, and slides back in below to create a future week. The project provides source files authored through Inkscape using free fonts, with PNG previews for those without a suitable SVG renderer.