The Steam launch of Dolphin, an open-source emulator for the Wii and the GameCube, has been delayed indefinitely (via PC Gamer). A blog post by the developers says that’s due to a Nintendo “cease and desist citing the DMCA” (an earlier version of the blog post simply said “issued a DMCA” but it has since been updated) after they’d announced plans for a Steam launch in March.

It is with much disappointment that we have to announce that the Dolphin on Steam release has been indefinitely postponed. We were notified by Valve that Nintendo has issued a cease and desist citing the DMCA against Dolphin’s Steam page, and have removed Dolphin from Steam until the matter is settled. We are currently investigating our options and will have a more in-depth response in the near future.

We appreciate your patience in the meantime.

Pierre Bourdon, who says he was involved with Dolphin for over 10 years in various capacities and named in the email from Valve, writes in a series of Mastodon posts that the notice was the result of a back-and-forth with Nintendo initiated by Steam and involved no DMCA notice, calling the action “just standard legal removals / C&D between two companies.”

One element that may be the point Nintendo is using to justify its request to block Dolphin lies in its distribution of the Wii AES-128 disc encryption, according to Bourdon. Rather than asking users to provide the key on their own, the software has shipped with the Wii’s “common key” embedded in its source code for many years.

Bourdon wrote on Mastodon that, unlike a straightforward DMCA takedown, in this case, Dolphin’s creators have no legal recourse to push back. This leaves the group at the whims of Valve, who he says could have ignored Nintendo at this stage without any repercussions.

We have reached out to Valve, Nintendo, and The Dolphin Emulator Project for further comment.

At least one other emulator, RetroArch, exists on the Steam platform, although that software doesn’t operate quite the same way Dolphin does. Where Dolphin directly emulates the GameCube and Wii consoles, RetroArch serves as a frontend into which emulator “cores” can be loaded, giving users a single centralized place to configure software settings for their emulators.