LXC,is a container building block
Don't forget, Curt, that Docker itself is open source and a large and thriving project. But assuming you knew that, LXC isn't excactly a challenger to Docker. It's a library of functions, tools and templates with which Linux containers may be built. Docker supports use of LXC and can support other approaches to container formatting. Somewhere down the road, open source container management systems are likely to nibble away at Docker's customewr base. If you mean, is something like LXC a market place threat to virtual machines, I'd have to say only lightly in the short run but significantly in the long run. Future cloud services are likely to become more container-based and LXC will be a building block for them.