"The SNK vs. Capcom (or alternately Capcom vs. SNK) series is a collection of video games by either Capcom or SNK featuring characters that appear in games created by both of these two companies. The "vs. series" terminology originates from the fact that many of these games (but not all) are fighting games.
As a rule, games in this series either contain SNK vs. Capcom or Capcom vs. SNK, the first company denoting the company behind the game's development. Games in this series appear for various platforms, including the NAOMI (arcade), Neo-Geo (arcade), PlayStation, PlayStation 2, Nintendo GameCube, Nintendo DS, Xbox, Neo Geo Pocket, Neo-Geo Pocket Color, and Sega Dreamcast."
Source: Wikipedia, "SNK_vs._Capcom_(series)", available under the CC-BY-SA License.