Battletoads is one of Rare's most beloved games from the NES era. An attempt to create a media brand that could rival the Teenage Mutant Ninja Turtles, Battletoads mixed platforming with side-scrolling combat, and is famous for its unforgiving difficulty level. It spawned several sequels (including a crossover with Double Dragon) and has recently been revived on modern systems.
Columbus Circle, the Japanese firm famous for its retro hardware and physical re-releases, is republishing the Famicom version of the game today. It's under licence from Extreme, the company which owns the rights of Masaya / NCS, the original publisher of the game in Japan back in the early '90s.
Before you get too excited, it's worth noting that this only relates to the Japanese version of the game, and we're sadly not likely to see a physical re-release of the NES version.
In the west, Battletoads was published by the now-defunct Tradewest. Tradewest became part of WMS Industries in 1994 and was rebranded as Williams Entertainment, Inc. and two years later would be renamed Midway Home Entertainment, Inc. Midway went out of business in 2010, but former Midway subsidiaries Midway Games Ltd (UK) Midway Games SAS (France) were purchased and renamed Tradewest Games Holding in 2009. The current status of that company is unclear, but it doesn't appear to be in business anymore.
Overall ownership of the Battletoads franchise now belongs with Rare's parent company, Microsoft.