  Past research on software product lines has focused on the initial
development of reusable assets and related challenges, such as cost estimation
and implementation issues. Naturally, as software product lines are
increasingly adopted throughout industry, their ongoing maintenance and
evolution are getting more attention as well. However, it is not clear to what
degree research is following this trend, and where the interests and demands of
the industry lie. In this technical report, we provide a survey and comparison
of selected publications on software product line maintenance and evolution at
SPLC. In particular, we analyze and discuss similarities and differences of
these papers with regard to their affiliation with industry and academia. From
this, we infer directions for future research that pave the way for systematic
and organized evolution of software product lines, from which industry may
benefit as well.
