Bleem! was a PlayStation emulator released for Microsoft Windows 98 and the Sega Dreamcast. Unlike the vast majority of emulators before and since, it was released as a paid product on store shelves. Bleem!, although very impressive for the time and capable of running on low-end PCs, had many compatability issues, with the only game that ran perfectly on Windows Bleem! being the US version of One, while the only games that could be run at all on Dreamcast were Tekken 3, Metal Gear Solid, and Gran Turismo 2, all with specialised emulators released on their own "Bleemcast" discs.

Sony would sue Bleem! twice over alleged copyright infringement, and despite all odds, Sony lost due to Bleem!'s use of screenshots in promo material and the PS1 BIOS being protected by fair use. However, a mix of legal fees and Sony threatening retailers stocking Bleem! products with subpoenas would force Bleem! off of shelves anyway, and its website would be replaced with an image of Sonic the Hedgehog mourning at a grave with the Bleem! logo carved on it. Bleem! would countersue Sony for anti-competitive activity.

The popularity of Bleem! would lead both Sega and Microsoft to attempt to work with Bleem! officially to make PS1 games run on Dreamcast and Xbox, though these plans fell through due to Sega being afraid of Sony's litigation, while the developers of Bleem! simply felt Microsoft wasn't paying high enough for the license for Bleem! (something they had come to regret in the years since).