If you select the image in Adobe Bridge you can choose File > Open in Camera Raw. Adobe Camera Raw will open the image using Bridge as the host application and you won't have to start Photoshop. There's no way to open Camera Raw without a host application.
If you can't find Adobe Bridge on your computer and you are a Creative Cloud subscriber, Bridge is one of the programs you can install using the Creative Cloud application.
Thanks, Conrad. So you have to go through another program to start Camera Raw. I see that if I double click my .cr2 file, Photoshop starts and then camera raw starts and opens the image. I guess going through Photoshop is fine. I thought that Camera Raw was its own program.
ACR is a Photoshop plugin - always has been.
(Wrong forum, incidentally - this is the Lightroom forum).
Right jadestag, Camera Raw is a plug-in and needs a host. Coincidentally, what Keith mentioned about this being the Lightroom forum might give you another answer: If you want to use the Camera Raw feature set without starting up any other program...you're basically describing Lightroom.