Flickr is almost like Xerox, or Kleenex, in that its name is in some ways inextricably linked to the service it delivers. There are many other photo sharing sites, of course, with similar (or perhaps even superior) features and options. Maybe it's because it is one of the first services that's managed to grow, add features, and consistently stand out from the others, it is often the first service people try, and the one many ultimately choose to continue with.
Though Flickr has a browser uploader, there are limitations. It is slow, and on occasion it won't successfully upload anything. Flickr has desktop uploaders available that are generally faster, and allow for more image and metadata manipulation prior to upload. And for years, the desktop uploader page has shown official options for Windows, and Macs, and mobile devices. For years, there has been one uploader option on that page -- a third party, cross platform (and very serviceable) -- that is Linux compatible.
jUploadr continues to be a great tool (and though updates aren't frequent, it handles basic Flickr uploading tasks well). Don't let the fact that it's the only Linux uploader listed on Flickr's site make you believe it's the only option, or that Linux targeted uploaders are one trick ponies.
