| Virtualisation, in the computing sense of the word, is | | | | retired from duty. This enables controlled application |
| all about abstraction. Abstraction takes out all the | | | | use when users are completely disconnected. |
| concrete details and substitutes something else in its | | | | Given this new technology, Microsoft now claims that |
| place. | | | | "application environments are no longer machine |
| Application virtualisation, specifically, is about | | | | specific, and machines are no longer user-specific". |
| encapsulating software programs from the underlying | | | | Citrix XenDesktop |
| operating system on which they operate. Virtualised | | | | Citrix XenDesktop claims to be able to centralise |
| applications are not installed as such. They are tricked | | | | applications in a data center to reduce costs, control |
| into thinking they are directly connected to an OS in | | | | encrypt data access and apps to improve security, |
| the traditional sense. A "virtualisation layer" is installed | | | | and instantly deliver apps to users anywhere in the |
| in the operating system to intercept all OS operations | | | | world. |
| the application would normally call. The virtualised | | | | Installfree, a relatively new competitor in the |
| application knows nothing about this virtualisation | | | | virtualisation world, claims their products can eliminate |
| layer. For example, when an application invokes a file | | | | complexity, increase portability & mobile computing, |
| access operation, the virtualisation layer would catch | | | | and achieve application compatibility. With their |
| this and perform some operation in lieu of a standard | | | | solution, IT departments can end temporary |
| file access call. | | | | workarounds, employee productivity loss, and |
| With application virtualisation you can run in | | | | application conflicts. |
| environments that are unsuitable for the native | | | | So much for application virtualisation. What about |
| application. You protect your OS and other apps | | | | server virtualisation? With server virtualisation, the |
| from bugs in the virtualised application. You can run | | | | entire operating system and its accompanying |
| incompatible applications next to each other with | | | | applications are abstracted. All applications and |
| minimal problems. | | | | system software have access to a virtualisation layer |
| A few of the key players in application virtualisation | | | | and have no idea they are not connected to a |
| are VMware, Microsoft, and Citrix. Some of their | | | | traditional OS and physical hardware. Basically, each |
| major claims to fame are as follows: | | | | Virtual Private Server (VPS) runs a copy of its own |
| VMware ThinApp | | | | OS. Customers have direct super user (administrator) |
| Thin App claims to package an entire application and | | | | access. |
| its settings into a single executable that is isolated | | | | Server virtualisation bridges the gap between "shared |
| from the operating system. You can run apps from | | | | web hosting services" and "dedicated hosting |
| any media without the need for administrator | | | | services". It provides independence to customers |
| privileges. ThinApp can maximise uptime during | | | | with regards to software but costs much less than |
| application migration and update. With ThinApp you | | | | physical dedicated server. Customers are free to |
| package once and deploy everywhere. | | | | deploy whatever software they choose, as all |
| Microsoft Application Virtualisation | | | | performance and security risks are confined to their |
| Microsoft's application virtualisation solution streams | | | | individual VPS space. This is not only useful for |
| applications on-demand over the Internet or via the | | | | production but can be used to test new software. A |
| corporate network to desktops, terminal servers and | | | | so-called "sandbox" is created within a VPS in order |
| laptops. Their solution automates and simplifies the | | | | to perform testing and debugging. Security issues can |
| application management lifecycle. Furthermore, it | | | | be explored and investigated in a "honeypot", a VPS |
| accelerates OS and application deployments by | | | | purposely set up with flawed/buggy code in order to |
| reducing the image footprint. | | | | observe security risks. |
| Such technology reduces problems end users | | | | Essentially, application virtualisation virtualises |
| experience when applications are upgraded, patched, | | | | application software, whereas server virtualisation |
| and/or terminated. It does not require any rebooting. | | | | virtualises the machine. Each solution has its unique |
| There is zero wait time for application installation and | | | | benefits and drawbacks. It is up to your IT |
| no un-installations are required when the application is | | | | department to find the right technology for the task. |