About Microsoft System Center Application Virtualization
Micrsoft Applivation Virtualization (or "App-V") can be considered as one of the first Application Virtualization products for Windows Operating Systems. Application Virtualization isolates programs, that are running on a Windows OS, from other applications and from the OS itself. This essentially is done by redirecting ("virtualizing") function calls to the OS' File System, Registry and other objects. Because System Calls are isolated, Application Virtualization allows to run multiple Versions of one application at the same time or to run applications, that usualy woulöd have file or registry conflicts, at the same time. Also, the underlying Operating System is protected, because Application Virtualization also may redirect modification attempts of System Components like Windows DLLs, cruicial Registry Keys and Values and others.
Besides this mechanism of Application Isolation, AppVirt ofthen is refered to as "Application Streaming". This, however, is not part of every Application Virtualization Product. In Application Virtualization Solutions, usually the Virtual Applcation Packge has to be downloaded to the Client, before it can be executed (whereas the Client can be a Windows Workstation or Terminal/Citrix Server). To decrease deployment time and network traffic when deploying new Packages, Streaming comes up. Streaming in that context means, that not the whole package is downloaded to the client. Rather, only a portion of the whole package (usually 20-40%) are transfered from a central server to the clients. This allows to start new applications quite fast, because they already run shortly after this inital portion has been transferred.
Microsoft App-V is the successor of Softricity's SoftGrid, . App-V's products cover both, Application Isolation and Application Streaming feature. In fact it was SoftGrid that established the terms "Application Virtualization" and "Application Streaming" to be synonyms.
Microsoft Application Virtualization History
Microsoft App-V is the successor of SoftGrid, a product that originally was created by the Boston based Company Softricity
Microsoft bought Softricity in July 2006 (however it was almost clear that this acquisition will happen some months earlier). Microsoft then released "SoftGrid 4.1" that was the first version which passed Microsoft's Quality Assurance Process. Almost at the same time Microsoft released SoftGrid 4.2 that mainly added Support for Microsoft Vista.
The current version is App-V 4.5, that mainly adds the concept of "Dynamic Suite Composition" and a broad range of supported Deployment Technologies.
App-V 4.6, that will add 64-bit support for the Virtualization Client is available since February 2010 and was updated to Service Pack 1 in February 2012