The Symphobia Colours Orchestrator from ProjectSAM is a sound library with real legato transitions for chords. It can be used to create orchestrations in audio applications such as for films, recordings, broadcast TV, and more.
The two ensembles recorded for Orchestrator are strings performing with choir and brass performing with woodwinds. A full set of legato chords is available for these two arrangements. Major and minor chords are mapped to two regions on the keyboard, allowing you to trigger and connect them using single keys.
In addition to the legato chords, a number of other ensembles are available, including legato double basses performing with choir basses, violin with soprano sustains, various staccato chords as well as a bonus set of alternative chord orchestrations.
Each instrument type in Orchestrator has a consistent region on the keyboard. Chords are always mapped to the same octaves, so are low basses and high sustains. This makes it easy to layer different sounds together. The included Multis give you a number of such combinations.