The best replacement for vmware workstation is virtualbox.

The best alternatives to vmware workstation are rated as following:
★★★★★  virtualbox
★★★★  vmware server
★★★★  virtual pc
★★★★  esxi
★★  hyper-v
★★  vmware player
★  vsphere
★  parallels
★  esx server
  microsoft virtual pc
  virtual box
  virtual pc 2007
  parallels workstation
  vmplayer
  vmware fusion
  xp mode
  gsx server

Your alternative for vmware workstation is not listed? Suggest!
Speaking about vmware workstation, one probably shouldn't forget about gns3.

Other search terms related to vmware workstation and their ratings are:
★★★★★ gns3
★★★ mac os x
vhd
You have in mind a companion for vmware workstation and it is not yet here? Propose!



Google Trends

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vmware workstation
virtualbox
vmware server