There is a saying that for every proprietary software, there are five open source alternatives out there (*). …Ok, maybe there is not such a saying, but nowadays you really do not need to rely on closed source tools for your developments anymore. And you should not! Because only by using FOSS tools we can ensure that really everyone can reproduce your open source designs.
Here is a list in a wiki we maintain at LibreCube: https://wiki.librecube.org/index.php?title=Open_Source_Software_Baseline
Be invited to post you suggestions here in this forum. Are there any FOSS tools you highly recommend for specific tasks? Are there areas where FOSS tools are missing (yet)?