Principles of Object-Oriented Software Development
[] readme course preface 1 2 3 4 5 6 7 8 9 10 11 12 appendix lectures resources

talk show tell print

Cross-platform development

Platform dependencies form an important category of architectural constraints. In particular, the opportunities offered by one platform may prohibit the deployment of software on other platforms. Nowadays, there are a number of (flavors of) competing platforms, as there are the Unix flavors (of which Linux is becoming a strong contender) and the Windows family, including 3.1 (almost extinct), Windows 95, NT, 98 and (in beta release) Windows 2000. Unix (for example Sun Solaris and SGI IRIX) has by tradition a strong position in the server market. However, Windows NT is growing rapidly in importance. The Windows family, clearly, dominates the (client) desktop market.

Cross-platform development

Unix vs NT


Research/GNU

Commercial
slide: Cross-platform development
Nevertheless, the need to support a variety of platforms will exist at least for some time, and consequently questions with regard to portability and cross-platform development may be important architectural issues.

Considering the opportunities for platform-independent or cross-platform development, we may distinguish between three approaches:

As we have discussed previously, many of the open standards, such as OMG CORBA, and proprietary standards such as Sun Java, aim at platform independence. Also, there are numerous GUI toolkits available that offer platform-independent support. A possible disadvantage of this approach is that the platform specific technology can usually not be profited from.

When it comes to porting applications from Unix to Windows 95/98/NT, we may look at AT&T U/WIN, which provides a POSIX extension for Win32, or Cygnus GNU-win32 support, which offers many of the GNU utilities and libraries for the Windows platform. Similar functionality, as well as support for Motif/X11 GUI capabilities, is offered by the (commercial) NuTCracker environment. (A detailed discussion of the technical merits of the various offerings is beyond the scope of this book. However, the interested reader may find more information in the online version of this book.)

The Windows platform is not only popular with end-users but also with many developers, who enjoy using the Microsoft Visual Studio suite of tools and (object-oriented) frameworks such as MFC. Recently, toolkits have entered the market that allow for porting Microsoft technologies (including Visual Basic, ActiveX and MFC applications) to the Unix platform, in particular Wind/U from bristol.com and Mainwin from mainsoft.com. As a word of warning, these toolkits are still terribly expensive. Yet for more information, consult the online version of this book.

For those who wish to develop directly on the Unix platform, but using Microsoft Visual Studio, there is Tributary, from bristol.com, which offers a Unix-server and client-extensions to Visual Studio.

Discussion

From an architectural perspective, it should not matter what platform is used for the actual development, nor for what target platform the software is being developed. In practice, however, given the preferences of the developers, the particularities of the platforms, and the instability of the (beta) software running on these platforms, the actual choice may make a big difference. As an admittedly weak advice, tune your strategy to your needs and experience! (And your budget.)
[] readme course preface 1 2 3 4 5 6 7 8 9 10 11 12 appendix lectures resources
eliens@cs.vu.nl

draft version 0.1 (15/7/2001)