I guess not many people ask this question because by default it is assumed that SAAS has to be accessed through the browser. And the truth is that the vast majority of SaaS applications are accessed via web and logical thinking.

But although we know that everything is not SaaS web and some are SaaS web apps, all the web applications are not and therefore there is no need to access them from a browser to retrieve. Saas reviewing concepts that relate to this issue are:

1.  Access to the software without installation or investment
2. Maintenance and upgrades of application by provider
3. Access via internet, ie from anywhere in the world.

None of them means that the application must be accessed through the browser, but sometimes it is more natural.

And then, if not accessed through browser, what other forms of access does it have? Through certain runtimes that allow code or perform other applications located on servers, ie out of your PC. The most popular are: Java Web Start Java JRE, Adobe Flash Player, Adobe Air and Microsoft Silverlight.

Java Web Start is installed with the Java JRE on client server and ensures that you’re running the latest version of the application on your dedicated server. You can run it from the browser or the desktop of the client.

Adobe Flash Player and Microsoft Silverlight are plugins that need to be installed in the browser to run applications located on the server. Apparently it seems that you are accessing it via browser and the application is running on common standards like HTML, CSS, DOM, JavaScript, XML but you’re actually running the runtime.

Adobe Air is installed on client runtime running applications located on the server. In the event of Adobe Air you can schedule when you want the application to be updated but it is a very easy task.

The most notable disadvantages are :

1. You need to install the runtime on your PC. Adobe Flash Player has it easier because 95% of all browsers already have it installed but  runtime no longer updates itself.
2. The access time to the application is greater at the first time
3. Increased consumption of resources of the client PC

The advantages would be :

Still keep the look of client applications lifetime. You do not have the limitations of the technologies associated with the browser (HTML, CSS, DOM, JavaScript, XML) in terms of compatibility, interface, etc.

All cross-platform (including Silverlight is), ie, the runtime can be installed on different operating systems and applications work the same way.

Development time is usually much smaller

In my opinion, saas have a relatively short comparison in all web users or those who purchase, happens to have a commercial use, I prefer this solution for all these advantages. For the rest, this solution with Adobe Flash Player (because of its ubiquity) also may be worth even the safest, if you want to reach a large number of users, using standard browser technologies.

And you, what do you prefer?