From Mac Guides
Copland was never released, but most features have found their way, over the years, into MacOS and Mac OS X. Many of the features contained in Copland are visible in OS 8; so many in fact that they are indistinguishable from each other to the untrained eye. Copland had the first live search, but wasn't fully matured. Mac OS X 10.4 (Tiger) was the first operating system to include this feature - Spotlight.
For a more in-depth view of Copland, visit: http://lowendmac.com/orchard/05/1108.html