Group awareness tools have garnered significant interest within the realm of computer-supported collaborative learning (CSCL), as they foster collaborative learning behaviors. However, in the context of a CSCL environment devoid of rich technologies, supporting group awareness is challenging. Contextualized in a teacher professional development course in a large normal university in southwestern China, this study followed a minimalist approach to develop group awareness support through collaborating authoring software. An 8-week-long quasi-experiment was conducted to explore whether supporting group awareness in project-based learning (PBL) through a minimalist approach could (1) improve the quality of group project, and (2) improve students' participation in collaborative learning. The sample consisted of 125 junior students. Students received regular instruction in stage 1 (week 1 to week 4) and instruction with group awareness support in stage 2 (week 5 to week 8). After each stage, students' group projects and self-reported surveys were analyzed qualitatively and quantitatively. It was found that supporting group awareness led to significantly better group performance but did not significantly influence student participation. Group awareness support also contributed to equal involvement among group members. Furthermore, cross-group awareness encouraged students to co-construct knowledge across groups. These findings might help practitioners in economically disadvantaged and technologically underprivileged areas to design group awareness support. It might also benefit instructors who prefer a light-tech solution to support CSCL.