Given the well-established merits of open source software (OSS), many profit-oriented companies actively participate in OSS communities, making significant contributions. Existing studies have predominantly focused on several advanced and specific questions regarding this phenomenon, mainly from the companies’ perspective, such as companies’ domination and withdrawal. A more basic and comprehensive understanding is missing, i.e., how OSS developers perceive such corporate engagement. Individual developers, including both volunteers and developers assigned by companies, are directly impacted by and have personal experiences with the consequences of commercial participation in OSS projects. This paper aims to bridge this gap by amplifying the voices of individual developers and providing valuable insights that have the potential to enhance companies’ participation in OSS projects. We conducted a survey involving developers from three OSS projects, i.e., Rust, OpenStack, and the Linux kernel, focusing on their attitudes and expectations regarding corporate involvement. We received 84 meaningful responses and analyzed their open-ended responses through thematic analysis. The results suggest that regardless of whether developers were paid or voluntary contributors, a prevailing attitude emerged – 67.9% of developers expressed a positive view of companies’ participation in OSS. The key idea behind their positive attitudes is perceiving commercial participation as a win-win for both the OSS community and companies. The Rust community remains more neutral when compared with the other two communities. We also surveyed and analyzed developers’ expectations of companies’ better participation, which can shed light on how OSS ecosystems can sustainably evolve with the companies involved.