How great? Finally, the world's best notation editor runs on Linux! This program is the only one that keeps me rebooting back to Windows for a very long time. I'm still waiting for a Linux native notation editors. So far MScore and NtEd look promising, but they are still under heavy development, and it would take years for them to replace Sibelius, not mentioning another years for a converter that will allow me to open hundreds of my old .sib files.
While sibelius 4 has been running on Linux for quite a while, the line break problem stops most people from runing it under Linux. The bug is, well, a bug. Minor, but annoying enough to render the software barely usable. Any text longer than one line will not render correctly, the software ignores the line breaks, so the all the lines will print one on another, making them impossible to read. To make things worse, it affects the time signatures, both numbers are printed on the same spot.
But now, thanks to the wine developers, the bug is gone for good. You can see from the screenshot that the time signatures are printed correctly, with Compiz fusion's wiggly windows effect applied.
So finally, Linux becomes a usable platform for musicians. Currently my favourite software lists include JACK (Low latency audio connection kit), Ardour (digital audio worksation) and finally, a notation editor, the one and only Sibelius 4.