Plymouth

Plymouth is used to show splash screens during system boot and shutdown. It is a more modern alternative to fbsplash and provides flicker-free animated boot splashes with a progress bar. It also has full systemd support. However, it does not provide eye-candy for the ttys in the way fbsplash does (meaning it shows no decoration on your consoles while the system is running).

Installation
can be installed using

When emerging Plymouth number of themes will be pulled in automatically.

However, genkernel cannot create an initramfs with a Plymouth theme included. Therefore either dracut or will be needed. From this point onward this configuration guide will continue with genkernel-next as it is marked stable and is essentially a drop in replacement for genkernel. The "plymouth" use flag needs to be enabled in.

OpenRC Configuration
The first step is to select a Plymouth theme. A list of all themes can be found using

Assuming you want to select the solar theme as the default theme:

Additionally, you need to enable this theme in the genkernel-next's configuration file:

Next, you will need to regenerate the initramfs using the  command:

Next, make an update to your Grub2 configuration to enable the splash screen during early boot. Append the options "quiet splash" on the end of the GRUB_CMDLINE_LINUX_DEFAULT variable, adjust the resolution in the GRUB_GFXMODE variable to match your desired resolution for your primary screen, and set GRUB_GFXPAYLOAD_LINUX to "keep" in order to preserve the graphics mode during boot.

Finally, run the  command to update grub2's boot configuration. This will set grub2 to be sure to include the changes you made when you updated  above.

You are done!

Systemd Configuration
Plymouth automatically registers itself with systemd to show a splash screen during shutdown/restart.

External Resources
Plymouth Main Project Page

Plymouth Source Code Page

An Early Gentoo Guide for Plymouth

Wikipedia Page