As others said, making it clear that Swift isn't only for Apple platforms seems important, this should be visible right from the homepage of swift.org. For this to be 100% true, the first requirement is probably to improve the dev experience on other platforms so that it is at least as good as it is for other popular languages as discussed in Crowdfunding world domination - #101 by tkremenek.
Making download links and documentation accessible right from the home page would probably have a good impact, in my opinion, many language users are expecting to be able to get started right away and any difficulty for doing that might lead them to think that using Swift anywhere outside of Apple platforms requires many hacks.
Highlighting the Swift community and generally showing all of the possibilities offered by Swift from the homepage would also be beneficial, why not with interactive and/or downloadable examples demonstrating the possibilities offered by third-party packages, the goal being to make a great first impression.
For the homepage layout, I would see a concise description of Swift, buttons for important actions such as "Download", "Documentation", "Contributing" etc... and below that why not :
- Online Swift playground similar to what can be found on the homepage of other languages (see haskell.org or python.org), with a "random example" button enabling users to get a good preview of Swift.
- News/editorial section with infinite scrolling (potentially subdivided into a few main categories) containing swift community news (major releases of packages, examples of using packages...), tips and tricks, Swift news (demonstrating new features when a new version comes out etc.)
Additional random ideas:
- Translating the documentation/website
- For potential contributors, a beginner guide to contributing to Swift, even for those without prior compiler project experience, would be great, why not detailed examples of fixing starter bugs ?
- Guides for interesting possibilities of Swift on all platforms (eg: "Using Swift for server-side development", "Swift for machine learning")
- If we identify common misconceptions made by Swift beginners, a section (maybe in the form of a FAQ) addressing those.