Appsense have applied eco thinking to their existing Performance Manager product. In a mailout by the company last week, Appsense promoted a high level white paper touting their existing Performance Manager product as being able to reduce energy costs by up to 40%, and as such reduce carbon emissions.
Essentially Appsense allow you to achieve this by reducing the number of servers you need to buy because their Performance Manager product optimises how your CPU and memory is utilised, thus you can fit more services on a single server.
In past years Performance Manager has been a popular product with Citrix farms. In this scenario you usually buy a gaggle of servers which run applications that may not efficiently utilise server resources. Applying Performance Manager to each Citrix Presentation Server ensures more users can access each server so you can reduce the number of servers in your farm.
Having personally deployed the Appsense products before to a number of enterprise customers, I can say it is a very interesting solution especially in Citrix farms but it does cost a pretty penny. However if you have a large server farm, keep in mind that Appsense may be willing to negotiate on the price.