Linux
Linux is an open-source Unix-like operating system kernel originally created by Linus Torvalds. This index catalogs the userspace and kernel programming interfaces exposed by Linux, including system calls, eBPF, ioctl, netlink, procfs, sysfs, GPIO, and security interfaces such as Seccomp, Landlock, and Linux Security Modules. It also covers ecosystem APIs for systemd and PAM.
APIs
Linux Kernel Userspace API
The set of stable userspace-facing interfaces exposed by the Linux kernel, including system calls, ioctls, eBPF, futex2, and the netlink protocol.
eBPF Userspace API
Extended Berkeley Packet Filter (eBPF) userspace API for loading and interacting with sandboxed programs running in the kernel.
Netlink API
Socket-based interface for communication between the kernel and userspace, used widely for networking, routing, and device configuration.
Seccomp BPF
SECure COMPuting mode with BPF filters, used to restrict which system calls a process can make for sandboxing and hardening.
Landlock
Unprivileged access-control framework allowing processes to restrict themselves and their descendants from filesystem and network operations.
procfs
Virtual filesystem mounted at /proc that exposes process and kernel information through a file-based interface.
sysfs
Virtual filesystem mounted at /sys that exports kernel object and device information to userspace.
systemd D-Bus API
The system and service manager API exposed by systemd over D-Bus for managing units, services, and the boot process.
Linux PAM
Pluggable Authentication Modules providing flexible, configurable authentication mechanisms for Linux applications.
udev
Device manager for the Linux kernel handling device nodes and hotplug events under /dev.