Digging Into the LDN

So, having made it through the launch of LDN yesterday, I thought it would be nice to take a step back  and point out what is the coolest functionality of the new site: the Linux Application Checker. This thing, I have to say, is one sweet application.

In the past, the best way to making a Linux application portable was to closely follow the LSB model as much as possible. And while I am a big believer in the LSB to make it easier to develop for Linux, I have learned there are a number of reasons why application vendors might not want to go for full LSB compliance.

To provide as many choices as possible, the new AppChecker tool is for vendors who are not (yet) planning on pursuing LSB certification as well as those who are, as it analyzes and provides guidance on symbols and libraries that go beyond the LSB.

AppChecker is easy to use from the start. After downloading the architecture-specific version of AppChecker, you merely unpack the tarball into a destination folder and run AppChecker from there. An embedded web server provides a universal interface for any architecture.

Once you point AppChecker to the binary for the application you want to test, the automated system compares the symbol table of the application's interfaces and libraries to the known values within the 30 LSB-compliant distributions. After the comparison is complete, a detailed report of which distributions your application should run on is provided. This app/distro matches give the developer a strong indication that, after some additional testing and a little tweaking, that application should run on the indicated matched distros.

So, while a positive result from AppChecker does not guarantee that your application will run on all distros out-of-the-box, it can lead you down the path of portability and hopefully reduce your support and porting costs. This allows developers to target the largest market possible and provide choice to their customers without too high of a burden or risk.

The AppChecker really shines when a mismatch is found; it not only tells you there is a potential issue with a particular distribution, it also specifically identifies the missing or incompatible interfaces. Links are provided from these reported interfaces so the developer can dig deeply into exactly how to modify or replace the interface to maximize portability, if they wish.

And, on top of all of this, the AppChecker still performs its original function--reporting on how far along an application is toward LSB compliance, if that is still a goal for the application vendor.

There are, of course, lots of sharp things about the LDN. Some ready to go, and some in the process of being built (that's what "beta" means). In the next few weeks, I hope to walk everyone though the features, and hopefully get some feedback on what's happening at the LDN!