Breaking changes

• The println builtin is now known as echo, shadowing the external echo.
• Changes on comparison builtins:
  • A family of string comparison builtins have been added, <s, <=s, ==s, !=s, >s and >=s (#238).
  • The is builtin is the new generic (shallow) equality predicate. The deep equality predicate deepeq is now known simply as eq.
  • The == builtin now compares numbers -- == 1 1.0 is true, while == a a throws an exception. To compare strings, use either ==s or is.
• Automatic use'ing has been removed. All modules must be used before use.
• The into-lines builtin is now known as to-lines.
• The history builtin has been removed; use $le:history instead (#267).

Other notable changes

• When run interactively, predicates that return false are now indicated with a ✗ sign.
• Completion listing now has black text over a light background (#184), and is no longer unnecessarily tall (https://asciinema.org/a/87937).
• Strings can now be indexed to obtain substrings (#243).
• The peach command, a parallel version of each has been added (#244).
• Multi-level modules are supported. For instance, the a:b module is the file ~/.elvish/a/b.elv (#249).
• When exceptions are thrown, a full stack trace is now displayed (#207, https://asciinema.org/a/88801).
• An unstable builtin -time has been added that shows the time to run a function.
• An unstable builtin -override-wcwidth has been added to override wcwidth.
• The navigation mode now supports previewing UTF-8-encoded text files (https://asciinema.org/a/89374).
• A variable $le:after-readline has been added. It is a list of functions to be called just after the line editor completes reading input, with the input as the sole argument.
• The auxiliary elvish-stub program has been removed, and elvish now always runs in foreground. As a nice side effect, elvish is go-gettable again.