Holding The Line is a collabrative writing effort involving about two dozen writers from the Wing Commander Aces Club. It covers the battles on the frontier to keep the Nephilim away from our homeworlds long enough for the Midway to close the wormhole gate in Wing Commander Prophecy.
You can find all four completed arcs of the story at this site. Be warned though, the story is already about 160 chapters long:
No, but you can download each of the four completed story arcs in one go. Just click on the download link (at the bottom of the chapter listings for each arc) and you'll get a zip file with all the stories.