Why I need Tiger? Because of hardware!
My notebook Samsung P29:
Celeron M 1,3GHz - family 6 model 13
RAM 1280Mb
ATI chipset
ATIRadeon9000IGP shared memory
ATA HDD and DVD
AC97 sound
BCM440X network adapter.
Principally there are two moments:
1. Video card controlled by ATIRadeon8500 family driver that PowerPC only in 10.5. The same I can say about nVidia drivers for NV30 family. They are Tiger only!
2. My chipset has 8259-pic controller with one-chip config. After detailed study I found that AppleACPIPlatform v1.0.3 is the last version that support such PIC-controller. All other versions give me kernel-panic at startup.
There is also problem that I have no HPET at all.
Previously I use 10.4.6 that is only system can be installed on such hardware. There are many internal mistakes in the version (USB, DMA and others) so I want to make better Tiger.
One note else. Any program has bugs. And OS 10.4 is not an exclusion. When Apple find some bugs it propose Software update but for Tiger only programs are updated. All drivers remains buggy. When I compare Tiger's and Snow sources I found corrections that doesn't related to OS version and can be applyed to Tiger's sources. It means I created drivers better then vanilla Tiger's drivers due to Apple's programmers working for Snow.

Software Update
I made full update of my system to 10.4.11 but before restart replace the follow:

Bootloader
I want to have DSDT patch. But it didn't occur with any previous bootloaders. Why? The laptop has clear ACPI1.0 structure but AppleACPI wants to have ACPI2.0 and it create it on the fly! I got memory dumps and found old DSDT address, not patched. Thus I create special version of Chameleon 2RC4 that apply patched DSDT to the same memory address. The restriction of the method is that new DSDT must be smaller then old. It is not a problem, just erase LPT, EPP, ECP devices. They are not supported by MacOSX. Old DSDT is quirky. Just recompile it with modern iasl I got Fn-keys support.
Chameleon-boot-for-Tiger
iasl-for-Tiger
DSDT and other ACPI tables can be extracted by the script

AppleACPIPlatform.kext and APIC
As I said I need old version 1.0.3. Other users may use modern version depends on chipset.  AppleACPIPlatform.kext.zip ( 229.65K ) Number of downloads: 190

Also I need to replace AppleAPIC to old version. But it is opensource so I can correct some internal mistakes of old version.
AppleAPIC.kext modded
It's a pity the ACPIPlatform 103 doesn't support _DSM method in DSDT. Looking for other solutions. -> Found! I made Natit that can be replacement for _DSM method.

Kernel
Vanilla kernel can't work with SSE2 CPU whatever EFI you may use. The only working version I found before is 8.9.1 by netkas. But it is non-EFI and set MacModel as ADP2,1. It is not good.
So I tried to create my version of kernel 8.11 to use EFI possibilities and SSE2 CPU. It seems to be not final version but it works.
mach_kernel.8.11.4
Also you need corresponding version of  System.kext.zip ( 131.41K ) Number of downloads: 185

The kernel will works also with Pentium 4 and may be with AMD. There are also patches for halt-restart and absent of HPET. Still no patches for non-constant TSC.
New version of the kernel 8.11.1. It uses other SSE3 emulator and have no graphics artifacts.

AppleSMBIOS
My bootloader supports SMBIOS patching so you can use vanilla kext. But I use kext from Snow 10.6.3 recompiled for Tiger. It seems to be better for this config.
AppleSMBIOS_1.5_Tiger

IOPCIFamily and IOPCCardFamily
My version of IOPCIfamily increases a stability of the system and avoids interrupt conflicts. But more sufficient that it corrects bus numbering for some hardware configuration that is the reason for PCMCI not working. You can take Tiger version from here. If necessary I can upload it here.
And then IOPCCardFamily kext depends on DeviceID and on MacModel. Thus it needs to be rewritten. Not sure that Chun-Nan correct it for your MacModel. My correction to Chun-Nan's IOPCCardFamily working for me.

USB
In the configuration I have good working vanilla IOUSBFamily as never before with 10.4.6. My bootloader provides some USB fixes but I still can't use DSDT patch because of _DSM method is not working. So now I use Natit with USB patch.(see 10 lines before). Fine!!! USB is able to wake, copying from USB stick at 16Mb/s.
Nontheless I recommend my driver created using Apple's workaround applied in Snow IOUSBFamily sources. This driver is better then vanilla Tiger's IOUSBFamily.

Decryptor
To use vanilla loginwindows.app and some other system parts you need some decryptor solution. It may be old dsmos. I created Tiger version of AppleDecrypt.kext.
Our new FakeSMC for Tiger

Battery status in the menu bar
There are no more needs for patched PowerManagement.bundle. Thanks for Chun-Nan for AppleACPIBatteryManager. It is only I need.

SpeedStep
Cause I have no HPET I have to delete AppleIntelCPUPowerManagement.kext. And I have no solution for speedstep. In progress... It's a pity but my Celeron M 350 doesn't support Enchanced SpeedStep so the technology is out of my interest.

Temperature and Fan Monitoring
Our FakeSMC was made for Tiger to show Temperatures and Fans. But my notebook has no any sensors

Other device drivers
I have special drivers for
ATI IXP150 ATA controller
AC97 Audio driver
ATIRadeon9000 video
VoodooHDA for Tiger @post #5 by jadran

Hey, Latest Chameleon works with Tiger, just dont use GraphicsEnabler, unless card is supported. 9800GT here.
Man it flies...

Latest Chameleon will not work if ancient computer contains ACPI1.0 only. My version performs conversion to 2.0 on the fly. This is a difference.

Mind sharing your sources??

My sources been always open at usually places.
http://www.projectosx.com/forum/index.php?showtopic=1106