This volume presents current views on the achievements made in the study of Systemic Functional Linguistics in both theory and application, and on potential domains and directions for its further development. The first part looks at strengthening theoretical research and description in system networks and seeks to deepen our understanding of the concept of choice and of the consequences arising from making choices in particular social contexts. It also makes comparisons of different models within SFL and of similarities and differences between SFL and other linguistic models. The second part sums up SFL's fifty years of refinement as a theory and goes on to offer an explicit definition of Applicable Discourse Analysis, presenting views on the potential areas, methods and criteria for verbal and multimodal discourse analysis, with examples. The final part of the volume discusses potential directions for SFL, including expanding SFL typological research into languages other than English, in countries other than the major English speaking ones, exploring solutions to the challenges faced by multimodal discourse, extending traditional translation studies to other modes; extending stylistics studies across different disciplines; exploring the potential of SFL to tackle the challenges confronting language education at both macro and micro levels; and achieving globalization in SFL across cyberspace.