$ git log --since=”2016-01-01” --pretty=format:”%an” --no-merges -- fs/btrfs | sort -u And then iterate for ext4 and xfs, and that comes to: 100 btrfs, 71 ext4

$ git log --since=”2016-01-01” --pretty=format:”%an” --no-merges -- fs/btrfs | sort -u And then iterate for ext4 and xfs, and that comes to: 100 btrfs, 71 ext4, and 63 XFS contributors over those 18 months. They are all healthy ecofilesystems.