GeoGebra is an emergent open-source Dynamic and Interactive Mathematics Learning Environment (DIMLE) (Martinovic & Karadag, 2012) that invites a modeling perspective in mathematics teaching and learning. In springs of 2010 and 2012, GeoGebra was integrated respectively into two online professional development courses on mathematical problem solving in a rural region of a Midwest state in the USA. Using GeoGebra as a primary tool for modeling and communication, fifty-three K-8 inservice elementary school teachers with no or little previous exposure to DIMLEs participated in the graduate level course, where they experimented with various resources of GeoGebra for mathematical modeling in the broad context of problem solving. The instructional team incorporated a variety of pedagogical components to support teachers' exploration of the new technologies and the mathematical content, including video-based demonstration, affective intervention, learning with children, and social and cognitive scaffoldings. After intensive online instruction, a 25-item questionnaire was administered to collect data on participants' attitudes, curricular awareness, mathematical content, and pedagogical reflection regarding the integration of GeoGebra. Based on results of the questionnaire (N = 45), this article provides a preliminary description of inservice elementary school teachers' learning experience in a GeoGebra integrated DIMLE setting, including an exploratory dimension analysis of the survey data. Overall, the use of GeoGebra challenged teachers' view about the nature of mathematics and student-teacher interactions and further enriched their mathematical knowledge and pedagogical choices. The course design, context, and implications for future efforts are discussed. An appendix contains GeoGebra Survey and Item Coding. (Contains 6 tables and 1 figure.) [This work was partially supported by the Illinois School Board of Education through an MSP Grant.]