The procedure to activate GF100TXRIII on linux is as follows:

 step 1: download the driver from
               rtl8139.c

 step 2: compile:
          The instruction for compiling the driver is include at the
          end of the driver file. (run this instruction at
          /usr/src/linux)

 step 3: insert the driver as module:
          insmod rtl8139.o
       parameter can be added by adding options=..... behind the istrruction
               0x16(bit 4):full duplex
               bit 0-3    :default port
       (run 'lsmod' to see if the module is inserted)

 step 4: bind your card to an IP address

    /sbin/ifconfig eth0 ${IPADDR} broadcast ${BROADCAST} netmask ${NETMASK}
       (run 'netstat -i' to see if there is a interface 'ne0')

 step 5: add your card to IP routing table, then add gateway also
    your card:
          /sbin/route add -net ${NETWORK} netmask ${NETMASK} eth0
          (should be able to ping local network now)
    gateway:
          /sbin/route add default gw ${GATEWAY} netmask 0.0.0.0 metric 1

 step 6: start inet deamon.
          /usr/sbin/inetd
          (you are on the network now)

*make sure that your kernel is built with network, fast_ethernet and module
support. Otherwise, you have to rebuild your kernel.
       (1:go to /usr/src/linux directory
        2:run 'make menuconfig' or 'make config'
        3:mark the options list above.
        4:exit and rebuild your kernel.
           make dep;make clean;make zImage
          the file 'zImage' will be at /usr/src/linux/arch/i386/boot/zImage
        5:modify /etc/lilo.conf.(this file specify where kernel image is)
        6:run 'lilo'  )

You cna run 'netconfig' which will do step 4,5,6 for you. This will create
'/etc/rc.d/inet1' and 'inet2' files. These two files will run at boot time.
Then just add a line at the beginning of 'inet1'.
       'insmod /your driver'path/rtl8139.o'

then your driver will work every time you boot.