Containers, as a form of lightweight virtualization, are frequently used to partition system resources among man applications or services. However, system resource availability, as presented by the kernel through the /proc filesystem, does not take into account container-imposed limits. lxcfs is a FUSE based filesystem which supports the containerization of cgroup and proc filesystems. It allows userspace applications to get more accurate information about resource availability and accordingly make better decisions about how much it can and should use. For instance, mysql can decide how much memory to use, or a compiler can decide how many threads to fork. This talk will discuss the history, details, and future of lxcfs.