Microsoft also pointed out two potential hot spots developers should look out for. The first involves serialization. "Any data serialized between versions of the .Net Framework is potentially fragile since serialization relies on the internal structure of the object," the white paper said. Also, applications that check for a particular version of the .Net Framework during setup could have problems, according to the white paper. Meanwhile, Microsoft said it will consider "reverting breaking changes" prior to the release of the final version of.Net Framework 2.0, "if they are found to impact applications."Asked if Microsoft still has time to address the problems that might arise through the compatibility testing the company is asking users to assist with, Cohen said: "Were still shipping in the second half of 2005. Therell still be time. We still have time until the product ships."Meanwhile, Jesse Kaplan, program manager in the Visual Studio CLR team, said the lessons learned from the testing "were not planning to use just for Whidbey," but Microsoft will use them in other development initiatives. Moreover, in the white paper Microsoft suggests various methods for avoiding or mitigating any compatibility issues. One is to test .Net Framework 1.1-based applications against .Net Framework 2.0 and make necessary changes to the application. A second method is to distribute .Net Framework 1.1 with their applications, and a third is simply to upgrade all applications to .Net Framework 2.0, the company said. Microsoft sings the virtues of Visual Studio. Click here to read more. "We want to test any kind of application," Cohen said. "Different applications behave differently with regard to the framework. We want to get as large a sample as we can." Added Roxe: "Were bringing applications in-house and testing them against the 2.0 framework, and were still looking for people to send us additional apps for testing compatibility." One ISV that has worked with Microsoft to test its application against .Net Framework 2.0 is Infragistics Inc., of East Windsor, N.J. "Microsoft is actively working with its customers on all levels to make the transition from the 1.1 framework to the 2.0 framework happen as smoothly as possible," said Steve Dadoly, Infragistics director of development. Dadoly said although Microsoft has its work cut out for it, he thinks the software giant is up to the task. "Due to the countless ways developers can build unique applications on the .Net Framework, it is virtually impossible for Microsoft and the ISV community to account for all of the possible scenarios customers may go through when upgrading an application," Dadoly said. "What Microsoft is doing for customers and ISVs like ourselves throughout the beta cycle for Visual Studio 2005 [with .Net Framework 2.0] is opening the line of communication for us to express any issues or concerns their customers may have and then responding to these concerns by either working hand-in-hand to help resolve the issue or simply sending a fix in a timely fashion. "When it specifically came to releasing a beta version of our NetAdvantage tool set for developing user interfaces for Windows Forms, ASP.Net and Tablet PC applications that was compatible with the recent beta of .Net 2.0, Microsoft played a key role in testing the tools to overcome any bugs we faced throughout our development cycle," he said. "This enabled us to make our beta available to our customers immediately after they received the latest .Net Framework 2.0 beta." In addition, Dadoly said Infragistics recently upgraded about 1.8 million lines of presentation layer source code from .Net Framework 1.0 to .Net Framework 2.0 as part of the companys effort to release the beta version of its NetAdvantage. But not everybody was as generous as Dadoly. Said one developer familiar with breaking changes related to the rollout of Windows XP SP2, who asked not to be identified: "For Microsoft to issue a white paper like this, applications must be breaking all over the place." However, SP2 was said to have up to 50 breaking changes and Microsoft officials said they could only identify fewer than 10 for the .Net Framework 2.0. The Microsoft white paper can be found at: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnnetdep/html/netfxcompat.asp Check out eWEEK.coms for Microsoft and Windows news, views and analysis.