Multiboot Specification
- Specifies interface between boot loader and OS, so any complying boot loader should be able to load any complying OS.
- http://www.xtrj.org/china-ukernel/l4/multiboot-english.pdf

Gujin Boot/Linux/System Loader
- For PCs, analyzes filesystems, supports Linux kernel and chainboot.
- http://gujin.sourceforge.net/

SysLinux
- Home of SysLinux (floppy), PXELinux (network), ISOLinux (CD-ROM), ExtLinux (ext2/3) utilities to boot Linux kernel; MemDisk, tool to boot legacy OSs (e.g., DOS) from nontraditional media.
- http://syslinux.zytor.com/

Multi-booting Solaris and Other Operating Systems
- Describes installing Solaris on a PC with other OSs, and joint use of Solaris boot manager and other boot loaders.
- http://multiboot.solaris-x86.org/

SyMon
- Boot manager with support of up to 36 primary partitions,
- http://symon.ru/usr/eng/about.shtml

zBoot Manager
- An effective boot manager, which allows the easy install and use of multiple operating systems on a single hard drive. Directly install other OSs to extended partitions and logic drivers.
- http://www.zbmsoft.com

SOLO: Shag/Os LOader
- Boot loader for Shag/OS which also supports, Linux and other PC operating systems. Includes source.
- http://www.csh.rit.edu/~shaggy/software.html#SOLO

OSL2000
- A universal boot manager allowing selection from a number of operating systems. Includes support for booting from USB, CDROM and other devices.
- http://www.osloader.com

Netboot
- Includes boot manager functionality and boots Linux, DOS and FreeBSD via a TCP/IP network using BOOTP and TFTP.
- http://netboot.sourceforge.net/

MATTsoft Boot Manager: MBTMGR
- Boots multiple OSs, including several on one FAT partition. Download, installation documents.
- http://www.penguin.cz/~mhi/mbtmgr/

MasterBooter
- Boot manager which can be used to install and maintain operating systems on a PC. Supports many operating systems. Shareware and registered versions available.
- http://www.masterbooter.com/

GAG - Graphical Boot Manager
- An open source graphical boot manager which supports up to 9 operating systems. Screen shots, version history and download.
- http://gag.sourceforge.net/

Extended-IPL
- OS boot selector. It can boot 2nd, 3rd or 4th hard disk and from an extended partition.
- http://www.tsden.org/ryutaroh/extipl/extipl.html

Extended Operating System Loader (XOSL)
- Archive of a project to create a graphical boot loader. Includes manual, FAQ and source code.
- http://www2.arnes.si/~fkomar/xosl.org/