Apps Under Wraps

Computerworld - To many IT professionals, application packaging may sound like the shrink-wrap you tear off a box, but for Doug Glenn, it's a critical step in controlling Windows application support costs. Glenn, senior technical analyst at electronics manufacturer Kemet Electronics Corp., uses a suite of tools from Plymouth, Mich.-based Wise Solutions Inc. to help control the installation process and deliver a consistent set of updates for some 200 applications his group has deployed on Kemet's 3,000 Windows desktops and laptops.
Under pressure to manage support costs, IT groups are increasingly locking down desktops using software distribution tools that automatically deliver applications, issue security updates and patches, and repair damaged applications on the fly. But these tools can't work effectively without a fundamental building block: application installation routines that have been properly packaged so that, once distributed, the Windows Installer (WI) service on each target machine can deploy them cleanly and without conflicts. Although these third-party packaging tools can help, the process of bundling applications isn't always easy, users say.
Packaging Benefits
The use of application-packaging tools has picked up since Microsoft Corp. introduced WI with Windows 2000, says Ronni Colville, an analyst at Gartner Inc. in Stamford, Conn. Prior to that, users and software developers created custom installation scripts that often overwrote Dynamic Link Library (DLL) files used by other programs -- a situation administrators dubbed "DLL hell" -- and that took vastly different approaches to the installation process.
WI has standardized that process by dictating the use of a Microsoft Installer, or .MSI package file, that specifies in detail how and where WI should deploy an application. A database containing configuration data, the .MSI file also lets WI keep tabs on issues such as attempts by one application to overwrite a DLL in use by another. And since it tracks all aspects of the application's installation, WI can support self-healing, or detection and transparent reinstallation of components that have been corrupted or accidentally deleted by the end user.
While software developers use packaging tools to create .MSIs to ship with their applications, administrators such as Glenn use them to customize those installation files by creating a supplementary .MST "wrapper" file called a transform, or to repackage older, noncompliant setup.exe files into .MSI files that WI can deploy. The tools read the .MSI file directly or run the noncompliant setup.exe installation program and compare snapshots of the machine's state before and after it runs to identify the changes made.

Judi Folkert, packaging programmer analyst at Herman Miller Inc.