The best replacement for vst is rtas.

The best alternatives to vst are rated as following:
★★★★★  rtas
★★★★  au
★★★★  vsti
★★★★  dxi
★★★  vst3
★★  dx
★  audio units
★  directx
★  au better
★  aax
★  daw
★  au ableton
★  au plugins
★  hardware synth
★  audio unit
  synesso
  au mac
  soundfont
  hardware synths
  32 bit vst
  tdm
  analog synth
  rta
  dxi plugins
  rewire

Your alternative for vst is not listed? Suggest!
Speaking about vst, one probably shouldn't forget about audacity.

Other search terms related to vst and their ratings are:
★★★★★ audacity
★★★ reason 7
★★★ ableton
★ logic pro
★ daw
cool edit pro
You have in mind a companion for vst and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of vst in all years. Click on graph for more.
vst
rtas
au