"Run anywhere" is really only descriptive of languages (e.g. Java), not implementations (e.g. Dalvik). You can't have a "run anywhere" implementation, unless you are grouping a bunch of implementations together...one for ARM, one for x86, one for FreeBSD, one for Windows, one for Minecraft, etc... because even under the same name the implementations would very significantly internally.

"Run anywhere" is a function of (1) the language spec (i.e. how much machine dependent behavior is permitted) and (2) the actual real-world support across platforms.

JS has the first, but the second is often conceeded, per the earlier comment.