At the moment, Ubuntu 17.04 (Zesty Zapus) is still using the stable Linux 4.9 kernel series, which have been marked as long-term supported (LTS) by renowned Linux kernel maintainer Greg Kroah-Hartman. The latest kernel version pushed into the Zesty repositories is based on the Linux 4.9.2 kernel, namely version 4.9.0-12.13. But it looks like the Ubuntu developers have been tracking the development of the upcoming Linux 4.10 kernel, and they managed to rebuild Zesty’s kernel packages on Linux 4.10 Release Candidate 4, announced last week by Linus Torvalds. The Linux 4.10 RC4-based packages are now ready for public testing.