Please do help with sorting out the current wiki documentation, as soon as exploring around the further pages gives you a grasp good enough to sort out the further things precisely and nicely as well.

Typical Hardware Requirements

At least 100 MB of RAM (A graphical desktop system may require up to 1 GB minimum.)
A writable storage device. (Required for the "sys" or "data" runtime modes (see below). Optional for making backups in "diskless" mode.)

Install Procedure

As with most linux distributions, the first installation steps usually consist of:

Downloading the proper stable-release ISO image for your computer's architecture, together with its sha256 checksum and GPG signature files, and then checking the sha265sum checksum of the downloaded image and verifying its GPG signature.
Either burning the ISO image onto a blank CD/DVD/Blue-ray disk with your favorite disk burning software, or flashing the image onto a bootable storage device (USB-device, CF-/MMC-/SD-card, floppy, ...).
Booting the computer from the prepared disk or storage device.

(If you need additional details see below, for installing on ARM systems, however, refer to Alpine on ARM instead.)

Contrary to most other distributions, the boot image already loads a complete, basic Alpine Linux system (command line environment). The boot process has first copied the entire system into the RAM memory, and then runs it completely from RAM. So that the running environment does not depend on reading from the (slow) initial boot media anymore.

Log in to the command line as the user root with its initally empty password.

Now a script called setup-alpine, other other setup-scripts and the apk package manager are available to configure the initial Alpine Linux system, install further packages, and prepare the system for the next boot:

The system can be configured to boot into one of three general Alpinelinux runtime modes:

diskless mode This is the default boot mode of the .iso images. It gets configured with setup-alpine if selecting "disk=none", and means the whole operating system runs extremely fast within RAM (saving unnecessary disk spin-ups, power and wear). A customized configuration and package selection may still be completely preserved on permanent storage media by using the "local backup utility" lbu and a local package cache (see this setup-alpine trick, it even allows that some applications may use the persistent storage).

data mode This mode is still accelerated by running the system from RAM, however the entire /var tree gets mounted from persistent storage. This location holds e.g. all log files, mailspools, databases, etc., as well as lbu backup commits and the package cache. The mode is useful for accelerated servers with large amounts of variable user-data that exceeds the available RAM size, and when the entire current system state should survive system interruptions based on the particular filesystem's guarantees. The boot device may remain to be the one initially used, and possibly even be immutable read-only.

sys mode This is the traditional hard-disk install. If this mode is selected, the setup-alpine script defaults to create three partitions on the selected storage device, /boot, swap and / (the filesystem root). This mode may be used for generic desktop and development machines, for example.

Additional Details

Booting from external devices

Insert the boot media to a proper drive or port of the computer, while it is turned off, and turn the machine on. However, depending on the computer it may be necessary to quickly press e.g. one of the `F7` `F8` F9` `F10` `Esc.` `F2` `F3` or `F12` key early to get to a boot menu selection for choosing the media to boot from.

Questions asked by `setup-alpine`

The setup-alpine script offers to configure several things, including:

Keyboard map (e.g. us and variant of us-nodeadkeys)
Hostname (The name for the computer.)
Network (e.g. automatic DHCP discovery)
DNS Servers (For privacy reasons, it is NOT recommended to use central servers like google's 8.8.8.8 etc.)
Timezone
Proxy ("None" for direct connections to the internet.)
SSH (Openssh is part of the default images.)
NTP (Chrony is part of the default images.)
Runtime Mode (Select between "diskless" (disk=none), "data" or "sys", all described above.)

Rebooting and using the new system

After the installation is completed, depending on the run mode, the initial installation media may be removed and the system may be power-cycled or rebooted directly with the new installation, to confirm that everything is working.

The command needed for this is poweroff or reboot.

Further Documentation

Directly booting an ISO file

Post-Install

TODO: Adding commmunity repository

Alpine post install packages and setup configurations for new users
Package Management (apk) (How to add/remove packages on your Alpine)
- Back Up a Flash Memory ("diskless mode") Installation
- Manually editing a existing apkovl
Init System (OpenRC) (Configure a service to automatically boot at next reboot)
- Multiple Instances of Services
Writing Init Scripts
Setting up Xorg

Upgrading Alpine

Setting up a ssh-server (Using ssh is a good way to administer your box remotely)
Hosting services on Alpine(Links to several mail/web/ssh server setup pages)
Changing passwords

Setting up a new user
Runnig programs and services in their own Firejail Security Sandbox

Further Help and Information

Running glibc programs Installation and Dev