What software do SpaceX engineers use?

Can you elaborate on the specific software tools and applications that SpaceX engineers rely on to design, develop, and test their cutting-edge spacecraft and technologies? Are there any proprietary or industry-specific software packages that play a pivotal role in their work? Additionally, are there any open-source tools or platforms that they integrate into their development process to enhance collaboration and efficiency? Understanding the software ecosystem within SpaceX is crucial for aspiring engineers and technologists alike.