1. Security Features: Alpine Linux focuses on minimalism and security, using the grsec/PaX patched kernel and stack protection measures such as SSP (Stack-Smashing Protection). On the other hand, OpenBSD is known for its strong focus on security, with security features like proactive audit of source code, memory protections, non-executable stack, and strong cryptography integrated into the system.
2. Package Management: Alpine Linux uses the package manager called apk, which is lightweight and efficient. It can handle package dependencies and supports package pinning. In contrast, OpenBSD uses its own package manager called pkg_add, which is designed for simplicity and ease of use.
3. Base System Components: Alpine Linux uses BusyBox, a small and lightweight set of common Unix utilities, as its base system components. It provides a small system footprint and reduces vulnerabilities. OpenBSD, on the other hand, provides a more complete and comprehensive set of base system components, with a focus on correctness and security.
4. Community and Support: Alpine Linux has a growing community and active development, with regular releases and updates. It has a strong focus on containerization and is widely adopted in the container ecosystem. OpenBSD, on the other hand, has a well-established and experienced developer community, with a focus on security and code correctness. It is known for its excellent documentation and security advisories.
5. Compatibility: Alpine Linux aims to be compatible with other Linux distributions, making it easier to port applications. It uses the musl libc instead of the more common glibc. OpenBSD, on the other hand, has its own libc implementation and follows a more conservative and strict approach to compatibility, which may require more effort to port applications.
6. Licensing: Alpine Linux uses a permissive open-source license, the MIT License, which allows for greater flexibility and integration with proprietary software. OpenBSD, on the other hand, uses a more restrictive open-source license, the BSD License, which focuses more on preserving the integrity and freedom of the code.

In Summary, Alpine Linux and OpenBSD have key differences in their security features, package management systems, base system components, community and support, compatibility, and licensing.