Forte is a "VST plugin host" application for Windows PCs. VSTs are software packages that synthesize sounds. There are thousands of VSTs in existence and more each day. For a good database of VST plugins, see kvraudio.com. However, VSTs are "plugins", and are not useful unless you add them to another software application called a "host". Many hosts exist today including Cakewalk Sonar, Reaper, Cubase, and Forte.
Forte was conceived in 2001 for the simple reason that there existed no VST host that made it easy to play music. There are many VST hosts around, but all of them are designed as studio tools to enable music production. They have tracks, and timelines, and tempos and key change markers, and MIDI and audio editing. These are all great (and we love these programs) but they are "Swiss Army Knives" with a million gadgets. Getting to the point of actually being able to play music on a MIDI keyboard through a VST plugin is a many-step process with these tools. What we wanted when we started Forte was a single purpose tool: something to just play VSTs.
Forte exists to turn the experience of playing VSTs into something as simple as sitting down at a piano (and just as fun.) Forte has existed on the market for 9 years now (!) Our emphasis is on stability for performance, not trying to get to the next major revision out as fast as possible.
To get started with Forte if you don't have any VST plugins, try downloading the free mda Piano at http://mda.smartelectronix.com/synths.htm
As I mentioned above, Forte is a single tasker. All of its features are in support of playing VSTs. There's no recording, playback, sequencing, timelines, tracks or any of that. There are, however, some unique features for playing live.
Forte can be configured to automatically start when you boot Windows. It can also be configured to automatically load a rack of VSTs, meaning that you can plug in your PC, hook up MIDI and audio cables, and when you turn it on, it will boot automatically and be ready to play your first song.
One of the key features of Forte is called a "Scene". Because Forte can host many VST plugins at once, it becomes a complex task to get them all configured the way you want them. Scenes make it easy to take a "snapshot" of your entire "rack" of VST plugins in their current state and store it for recall. Be creating several scenes, you can the switch through different configurations of plugins very quickly. Scenes can be organized into Songs and Setlists, making it easy to use scenes as building blocks for performance sets. For example a song might require a grand piano and an organ for the first half and an electric piano and a clavinet for the second half. Add two plugins and configure them for the piano/organ, create a scene to preserve that setting, and then create another scene with the plugins reconfigured for the second half. Name them appropriately and then you can easily switch in the middle of the song. In fact, you can even get Forte to listen to a specific MIDI event, and advance to the correct scene automatically! Imagine playing the 1st half of the song, stepping on a pedal to advance to the next scene, and continuing to play through the second half.
Now imagine that with about one hundred scenes. It works. Professional musicians have built big rigs with a dozen VSTs and many scenes, and they play through that set every night.
Bringing a computer on stage seems like high-risk behavior but it is the way of the future. Many musicians are doing it now and more all the time. If you choose to use VSTs for performance, wouldn't it be nice to have some tools built into the host to help you become comfortable with your rig's reliability? Forte has two major features designed to help you ring out a performance system. First, it has a "stress test" that simulates you playing on stage. If you load your rack of VST plugins into Forte and start the stress test, it will jam huge amounts of MIDI down the plugins' throats while thrashing between scenes. The intensity levels are adjustable, but the point is that its doing what you would be doing on stage but much more aggressively. Its trying to punish the VSTs and see if they break. Not all VSTs are up to the task, so its good to know up front!
Also, if you find a particular rack of VSTs to be reliable, you can preserve a "manifest" containing the versions of all the VSTs, the OS libraries, the audio drivers, and critical Forte settings. Later, if you do encounter problems, you can compare this manifest against your current one and look for any changes in your PC configuration.
So in summary, Forte exists to play VSTs as opposed to compose or produce with them. We've had years to polish Forte and many musicians are using it professionally every night.