For a better explanation here are a couple of paragraphs from the readme:
The lightweight installer (lwt_install) is a free tool designed to support embedding IBM Informix Dynamic Server (IDS) on Windows platforms. It can be used as a deployment tool to redeploy pre-configured IDS instances (INFORMIXDIRand optional data spaces). Similar to the IDS installer, the lightweight installer supports certain customizations during deployment - the key difference is that the lightweight installer is designed to deploy pre-configured instances rather than set them up from scratch at install time.It can also serve as a data server instance manager (for example to clone and create new instances on the same machine).
The lightweight installer is a command line utility designed to be calledprogrammatically or from a script as part of an application installation, and therefore supports completely silent IDS deployment. To allow better control of deployed instances and post-deployment ease-of-use, the lightweight installer takes a number of parameters from the command line. Editing the onconfig file gives the most granularity in configuring an IDS instance. Inessence, lwt_install is a lightweight alternative to the IDS silent installation mechanism for deployment.
You can find it in the Miscellaneous Routines and Utilities section of the IIUG Software Repository (as well as the DBA and C sections), or jump directly to it: http://www.iiug.org/software/index_all.html#lwt_install.
If you give it a try please provide feedback to Tosin and myself. What would you like it to do? What does your ideal deployment tool do? We'd like to see the functionality of this tool enhanced and coverage extended to other platforms.