HelpAid

HelpAid is a program made to convert text files coded with keywords to HPF and RTF items, which are required by help compilers. It comes in handy if you're looking to generate and implement user documentation into your personal software products.

Old, yet functional help authoring tool

The setup operation is speedy and simple, since there are no special settings, software requirements or third-party offers involved. However, it's obvious that the application hasn't received updates for a very long time. The installer's fullscreen mode and gradient background color remind us of earlier Windows editions.

Simple GUI for compiling help files

The interface is represented by a small window with a plain appearance, which takes a straightforward approach toward the whole conversion procedure, showing three buttons on a yellow background.
It's possible to specify the HLN file you want to process using a built-in file explorer. Unfortunately, drag-and-drop and batch processing are unsupported, so you can convert only one HLN object at a time.

How it works and user guide

HelpAid warns you that the file may not be properly compiled if the path contains a blank, and lets you know if it was processed normally or not. The new help file can be created with one click and opened to inspect results without leaving the app's interface.
An integrated guide offers to teach you how to write help topics in a simple text format with any word processor. It describes document structure and formatting keywords, such as copyright, colored text, extended character set, and bitmap images.
Note that help files have been replaced in Windows Vista by HTML and XML files.

Conclusion

HelpAid doesn't have rich options, hasn't been updated for a while, and doesn't seem to be in development anymore. However, it may give you some insight into compiling help files.