intro: Clarify what LinuxBoot is

Signed-off-by: Philip Molloy <philip@philipmolloy.com>

src/intro.md

@@ -10,12 +10,23 @@ This is the official “LinuxBoot Book” for the LinuxBoot project. The book:
 
 ## What is LinuxBoot?
 
-LinuxBoot is a project that aims to replace specific [firmware](./glossary.md)
-functionality with a Linux kernel and runtime. Over the years this project has
-grown to include various initiatives with the overarching goal of moving from
-obscure, complex firmware to simpler, open source firmware.
+Generally, LinuxBoot is based on the idea of replacing proprietary or
+corporate-driven late-stage boot [firmware](./glossary.md) with the Linux
+kernel and a open community userland. That idea has grown into a project that
+over the years includes various initiatives with the overarching goal of moving
+from obscure and complex firmware to simpler and open source firmware.
 
-The goal of LinuxBoot is to reduce the role of firmware to a small,
+The project consists of the [linuxboot](https://github.com/linuxboot/linuxboot)
+build system that builds a boot payload consisting of a Linux kernel and an
+[initramfs](https://de.wikipedia.org/wiki/Initramfs) that contains a Golang
+userland built using [u-root](https://github.com/u-root/u-root).
+
+More recently other projects have popped up based on the same idea:
+
+- [k-boot](https://github.com/BayLibre/k-boot) developed by BayLibre
+- [nmbl](https://github.com/rhboot/nmbl-poc) developed by RedHat
+
+These projects all attempt to reduce the role of firmware to a small,
 fixed-function core whose only purpose is to get a flash-based Linux kernel
 started. This “bare essentials” firmware prepares the hardware and starts a
 Linux kernel and a userland environment will run on the machine. Go is the