Firstly... I've been using Ubuntu for several months now but I still consider myself a noob.

My girlfriend has Fedora (not sure which version... prolly 5ish... she has not used that computer for quite awhile). She would like to experiment with Ubuntu but still use all the aps and data that she presently has on her computer. I realize that she could play with the live disc but that wouldn't give access to her apps, or would it?

The main question. I know that it is always recommended that one starts with a clean slate but hypothetically, after ghosting the drive to give oneself a way back, is it reasonably POSSIBLE to install one version of Ubuntu over Fedora and keep all the directories, apps and data in place but installing a new kernel etc? ...Or are there differences in the filesystem or app dependencies?

Thanks,
Christopher

Theoretically it is probably possible, but in practice it is not a good idea. You will almost surely run into problems because of different package systems.

The best way to go about this is to ghost the drive. Now you can go back to fedora if you don't like ubuntu. Then, backup the home directory. This will keep documents as well as application configs. Now, install ubuntu. You will lose your Fedora install at this point. After ubuntu is installed, copy the home directory back to the disk. Then, use synaptic or aptitude to install all of the applications you want. If it's the same application, it should read its previous config from the home directory.

Not a perfect solution, but that's what I would do.

I would say partition your Hard drive via Ubuntu liveCD with Gparted-leave the fedora at the beginning of your 1st partition-that way it won't be erased, use the remaining space for the ubuntu install + swapspace partition.
SDA1(or HDA1) (Fedora) /(root) Primary partition EXT3 xGB (where x=?however much space you wanna give to Fedora-let's say 10GB maybe)

SDA2(or HDA2) Ubuntu /(root) Primary partition EXT3 xGB(10-up GB)

SDA3(HDA3) Swapspace 2xyour RAM (so, if you have 128MB RAM, make your Swap partiton at least 256MB or a little more)

You can also create a FAT32 partition after the swap partition and use this for storage. Using the livecd you can even retrieve your files and save them by transfering them to a USB. That's how I saved my stuff when I screwed up XP and it would'nt boot. I inserted Ubuntu 8.04 livecd, booted to the Ubuntu desktop, went to the menu-Places-myharddrive and pulled all my stuff(copy/paste dragndrop) onto the Ubuntu desktop, then transferred them to the USB. I could have saved my XP with the Ubuntu disk, but being an ignorant newbie I said screw M$ and installed Linux and now I'm free.
I'm using Slackware 12.2 on SDA1, Xubuntu on SDA2, SuperUbuntu on SDA3 SDA4 is an Extended partion that contains both my Swap and my FAT32 storage-See screenshot-When I installed both SuperUbuntu and Xububtu I resized the Slack partiton and SDA2&SDA3, and my Slackware installed remained unaffected.
NOTE-IF YOU SCREW SOMETHING UP INSTALLING UBUNTU DO NOT REBOOT AND YOUR STUFF MAY STILL BE THERE-TO FORCE A REBOOT IF SAY THE PARTITIONER FREEZES OR YOU PICKED THE WRONG PARTITION TO ERASE-USE ALT+PRINT SCREEN BUTTON, WHILE HOLDING THOSE TWO DOWN ENTER R E I S U B-THIS WILL FORCE AN INSTANT REBOOT.

Thats what I've done, and it works well for me.

Windows - 20gigs
Ubuntu swap - 3gigs
Ubuntu / - 30gigs
/disk - 400gigs.

The 400gig drive, has all of my data on it (Music, office files, videos, etc..) I can access them easily from Ubuntu by just mounting the drive. I done it this way, because one of the few reasons I have Windows, is I have a Zune. I usually get all my music under Ubuntu, use easytag to edit it, etc.. Then save it to my Music folder which is on the shared partition... Boot Windows, and my Zune is sync'd to that folder.

IGF

I would assume that if I ghost it onto a USB drive then I could forego backing up the home directory, no? I could just use the ghost to get the home directory files from, yes? Or am I not thinking through something here?

Thanks for your help. :-)

-Christopher