what is the history of vst and vsti

The VST interface specification and SDK was released in 1996. Coinciding was the release of Steinberg Cubase 3.02. Included with Cubase were the first available VST format plugins. Espacial, Choirus, Stereo Echo and Auto-Panner.^[1]
The VST interface specification was updated to version 2.0 in 1999. One of the additions was the ability for plugins to receive MIDI data. This allowed for the introduction of VSTi (Virtual Studio Technology Instrument) format plugins. VST Instruments can act as standalone software synthesizers, samplers or drum machines.^[2]
Neon^[3] was the first available VST Instrument (included with Cubase VST 3.7). It was a 16-voice, 2-oscillator virtual analog synthesizer.^[4]
The VST interface specification was updated to version 2.4 in 1999. Changes included the ability to process audio using 64 bit precision.^[5]
The VST interface specification was updated to version 3.0 in 2008. Changes included:^[6]

• Audio Inputs for VST Instruments
• Multiple MIDI inputs/outputs
• Optional SKI (Steinberg Kernel Interface) integration