We do not believe that we are in violation of the SugarCRM Public License. From day one, it has always been our intention to follow both the letter and the spirit of the SugarCRM Public License. We have also gone out of our way to work with the folks at SugarCRM. In our opinion, although they have released their product as open-source, they do not follow the spirit of open-source by rebuffing the efforts of companies like SplendidCRM and vtiger. SplendidCRM would have been a perfect companion product in their battle for market share against companies such as Salesforce.com.
I don't believe that we specifically reference "SugarCRM 3.5.1" anywhere, however we do mention "Version 3.5.1" on the About page because that is the feature set that we originally targeted. Actually, the original motivation for using the same version number was an attempt to allow the SugarCRM Plug-in for Outlook to work with the SplendidCRM server product. However, it would seem that the SOAP implementation of SugarCRM precluded this from happening. But, since the SplendidCRM Plug-in for Outlook does indeed work with the SugarCRM server product, we thought it best to continue to synchronize this data element.
I'm going to follow your cola analogy as I respond to your next question. Think of SplendidCRM as Pepsi and SugarCRM as Coca-Cola. Coca-Cola is 100 years old, but 50 years ago, the Pepsi product appeared. Why, simply because there was a market for a similar but different product. The same is true for SplendidCRM.
SplendidCRM specifically targets companies that prefer Microsoft-centric applications. If your company runs their database on Microsoft SQL Server and their web servers on Windows Server 2003, then the best CRM for you is SplendidCRM.
As for differences, we hope to reach a point where there are no functional differences. Today, our feature set is similar to SugarCRM Open-Source 3.5.1, with a few exceptions. For example, we do not offer any reporting services in our first release. This is something we hope to quickly address, but we will do so in a Microsoft-centric way.
If I can just make a comment as an end-user, for me, the fact SplendidCRM runs on SQL Server and uses ASP.NET is a strong advantage. We use Microsoft platforms and we would not use SugarCRM because of its requirements for PHP and MySQL.
You might ask why bother translating books into other languages - after all, the English version may exist. However, that does not help those who enjoy literature yet do not speak that language in their country.
Same here too. Plus, I do not know if it is just me, but SplendidCRM is many times faster than SugarCRM.