You can filter the elements in a DITA topic by the attribute values. You can write a single topic, and set the required attributes to the conditional elements. You can then use the filter by attribute feature to filter elements based on the attribute values.
For example, in a specifications topic, you can set the product attribute to framemaker and robohelp on elements in the topic. Also, if the topic contains conditional content based on output, set the audience attribute to print (for PDF output) and web (for Web output). You then produce different output, based on the filters that you apply on the product and audience attributes.