The tools used to author Printed Documentation have been around for quite some time and haven't changed all that much in that time. AdobeFrameMaker is still the dominant player in the Printed Manual market. FrameMaker is an excellent tool and well worth the effort of learning it. However, it is a steep learning curve. It is a complex tool with an unfriendly interface.
MS Word is getting more and more complex with each release. It has captured a large portion of the Technical Publications market and its market share is growing all the time. However, Word has issues and its not just that I am rarely "Writing a letter". There are significant issues withits capacity to handle ordered and unordered lists. There are alsocompatibility issues between Word 97 and Word 2000 that can have a significant on the general well-being of DTP professionals.
Other than MS Word and FrameMaker, there aren't any major players. However, InDesign is becoming more common. QuarkExpress and PageMaker are used frequently for smaller, often marketing-type, documents.
There are a wide range of Help technologies varying depending on theplatform used to deploy the Help and also the preference of the Help author. Examples of Help technologies include:
All of these Help formats are generated using one of many Help authoring tools. The most common of these being RoboHelp.