This is what worked for me:

Oracle VM Virtual Box.
https://www.virtualbox.org/wiki/Downloads
Double click, click on run, and then accept the defaults
If it asks would you like to install this device software (happened several times for me), click install

To start virtual box, click on the icon:
Oracle VM Virtual box
THen click "NEW" button to create a new virtual machine.

Type in name, e.g. Fedora, it wil automatically choose Linux for OS type, and then
select Fedora (64 bit).
Next, recommnded memory: I used 1024 MB.
Create virtual hard drive, accept default (VDI) on next screen.
Dynamically allocated.  Give the virtual hard drive a name, and then accept the 8GB size (unless this is too large for your computer).  Then click finish.  Now you see Fedora is a listed virtual machine.

Before you start your virtual machine, download fedora iso image, and burn it to DVD (you can install without this step, but I had the DVD so I'm not exactly sure how to do that - but the user manual explains this a bit: http://dlc.sun.com.edgesuite.net/virtualbox/4.2.12/UserManual.pdf

Start the Fedora virtual box by double clicking, and insert the iso image DVD into your DVD player. 
Fedora will start up, and ask you a bunch of questions.  First, select your language, etc.  
About the disk: select yes continue about unpartitioned space.
Hostname: default is fine.  Time zone: default is fine.  Root password - don't forget what you type.
Next - it asks you about how to use the space. 
Click on Use free space - replacing existing unix might be fine since you don't have anything in it, but using free space is safer.  Make sure that "Review and modify partitioning layout" is selected, and also "Use LVM" but not Encrypt.  Then click continue, and on the next screen verify that the size of the "vg" is approximatly what you chose to use as your virtual hard drive, e.g. 7680 MB for me and I used 8 GB disk.
Click next, and then OK to create partition.  Then next (install boot loader on /dev/sda)
On next screen, be sure to select "software development" so that you have compilers, etc.
Then "next: will begin installation.  Go have some coffee or tea as this will take awhile.  When it is done, click on the reboot button (but first remove the iso-image DVD).

############################### Installing XPPAUT ###########################3

After you log in, start firefox (under activities) Download xppaut from http://www.math.pitt.edu/~bard/xpp/xpp.html
Click Download, and then Source code for the latest version.  
Then, open up a terminal window (click activities, then applications, system tools). 
type "cd Downloads" (cd = change directory)
type "ls" and xppaut.latest.tar.gz should be listed.  (ls = list directory)
type "cd ../" to go back up into main directory
then "mkdir xpp" to create a new directory for this code  (mkdir = make new diretory)
then "mv Downloads/xppaut.latest.tar.gz xppaut/" (ms = move file to new location)
and "cd xppaut" to get into that directy.
type tar -xzf xppaut.latest.tar.gz (tar is a command to unpack/uncompress the file).
Then, cd into the directory with the code ("cd xpp"), and edit the Makefile as follows:

gedit Makefile
Delete "#" in front of the line beginning
CFLAGS=   -g -O -m64 
and
LDFLAGS= -m64

and place "#" in front of line beginning 
"CFlags= - g - pedantic"
and
"LDFLAGS = -m32

save the file and exit, and 
then type "make"
It will compile.  To test, type
./xppaut &

If it does not compile, edit the Makefile again and
put "#" infront of the lines saying
DESTDIR =
BINDIR = /usr/X11R6/bin
DOCDIR = /usr/share/doc/xppaut
MANDIR = /usr/local/man/man1

then type make
and it will recompile, then test again.
./xppaut &

then select the ode directory, and then randomly pick a file.  

It would be a good idea to download the xppaut tutorial and try it out.