Customer-specific software can provide a competitive advantage compared to general-purpose software. A software product line (SPL) aims at tailoring customer-specific products from a set of reusable features. It is well known that systematic reuse of features potentially leads to significant gains such as faster production with low costs and high quality. In practice, building enterprise software product lines might become a laborious and error-prone task when we take into account the use of current implementation techniques. Successful development of modern enterprise software product lines requires the convergence of multiple views (e.g., domain experts, interface designers, and developers), which are usually managed via domain-specific concepts. In this case, each participant of the development process has a particular working language to solve specific problems to its expertise. The challenge of integrating these differences into the engineering process, avoiding the potential cacophony of multiple different languages, is the heterogeneous configuration knowledge problem. In this thesis, we examine the current shortcomings on the specification of heterogeneous configuration knowledge and as a solution we propose the notion of Domain Knowledge Modeling Languages (DKMLs). The purpose of DKMLs is to put in evidence the domain concepts and their programming interfaces, which help to reduce source code obfuscation and increase feature comprehension. Moreover, evidencing the domain-specific concepts, we are also able to prevent inconsistencies on products by detecting errors in the entire software product line. Another result of this research is the GenArchPlus, an extensible tool that supports the flexible incorporation of DKMLs in traditional software product line engineering. We emphasize the benefits of GenArchPlus, including simplicity, expressiveness, and being framework independent. Finally, we illustrate and evaluate the use of DKMLs in three different product lines.