diff --git a/src/lineedit.cpp b/src/lineedit.cpp
index efb552a..254cbfe 100644
--- a/src/lineedit.cpp
+++ b/src/lineedit.cpp
@@ -19,6 +19,7 @@ enum class TtyEscape {
   CtrlF = 6,
   CtrlH = 8,
   Tab = 9,
+  LF = 10,
   CtrlK = 11,
   CtrlL = 12,
   Enter = 13,
@@ -244,6 +245,7 @@ class LineEdit {
     if (nread <= 0) return false;
 
     switch (TtyEscape(c)) {
+      case TtyEscape::LF:
       case TtyEscape::Enter:
         return false;
         break;
diff --git a/valeri-mode.el b/valeri-mode.el
new file mode 100644
index 0000000..0fe66e0
--- /dev/null
+++ b/valeri-mode.el
@@ -0,0 +1,115 @@
+;;; valeri-mode.el --- a major-mode for editing Valeri programs  -*- lexical-binding: t -*-
+
+
+(require 'comint)
+
+(defcustom valeri-default-application "valeri"
+  "Default application to run in Valeri process."
+  :type 'string
+  :group 'valeri)
+
+(defcustom valeri-default-command-switches (list)
+  "Command switches for `valeri-default-application'.
+Should be a list of strings."
+  :type '(repeat string)
+  :group 'valeri)
+
+(defcustom valeri-prompt-regexp "[^\n]*\\(valeri>[\t ]+\\)+$"
+  "Regexp which matches the Valeri program's prompt."
+  :type  'regexp
+  :group 'valeri)
+
+(defcustom valeri-traceback-line-re
+  ;; This regexp skips prompt and meaningless "stdin:N:" prefix when looking
+  ;; for actual file-line locations.
+  "^\\(?:[\t ]*\\|.*>[\t ]+\\)\\(?:[^\n\t ]+:[0-9]+:[\t ]*\\)*\\(?:\\([^\n\t ]+\\):\\([0-9]+\\):\\)"
+  "Regular expression that describes tracebacks and errors."
+  :type 'regexp
+  :group 'valeri)
+
+(defvar valeri-process-init-code
+  (mapconcat
+   'identity
+   '("")
+   " "))
+
+(defvar valeri-process nil
+  "The active Valeri process")
+
+(defvar valeri-process-buffer nil
+  "Buffer used for communication with the Valeri process.")
+
+(defvar valeri--repl-buffer-p nil
+  "Buffer-local flag saying if this is a Valeri REPL buffer.")
+(make-variable-buffer-local 'valeri--repl-buffer-p)
+
+(defun valeri-get-create-process ()
+  "Return active Valeri process creating one if necessary."
+  (valeri-start-process)
+  valeri-process)
+
+(defun valeri-send-string (str)
+  "Send STR plus a newline to the Valeri process.
+
+If `valeri-process' is nil or dead, start a new process first."
+  (unless (string-equal (substring str -1) "\n")
+    (setq str (concat str "\n")))
+  (process-send-string (valeri-get-create-process) str))
+
+;;;###autoload
+(define-derived-mode valeri-mode lisp-mode "Valeri"
+  "Major mode for editing Valeri code."
+  :group 'valeri
+  )
+
+;;;###autoload
+(defalias 'run-valeri #'valeri-start-process)
+
+;;;###autoload
+(defun valeri-start-process (&optional name program startfile &rest switches)
+  "Start a Valeri process named NAME, running PROGRAM.
+PROGRAM defaults to NAME, which defaults to `valeri-default-application'.
+When called interactively, switch to the process buffer."
+  (interactive)
+  (setq name (or name valeri-default-application))
+  (setq program (or program valeri-default-application))
+  ;; don't re-initialize if there already is a Valeri process
+  (unless (comint-check-proc (format "*%s*" name))
+    (setq valeri-process-buffer (apply #'make-comint name program startfile
+                                    (or switches valeri-default-command-switches)))
+    (setq valeri-process (get-buffer-process valeri-process-buffer))
+    (set-process-query-on-exit-flag valeri-process nil)
+    (with-current-buffer valeri-process-buffer
+      ;; enable error highlighting in stack traces
+      (require 'compile)
+      (setq valeri--repl-buffer-p t)
+      (make-local-variable 'compilation-error-regexp-alist)
+      (setq compilation-error-regexp-alist
+            (cons (list valeri-traceback-line-re 1 2)
+                  compilation-error-regexp-alist))
+      (compilation-shell-minor-mode 1)
+      (setq-local comint-prompt-regexp valeri-prompt-regexp)
+
+      ;; Don't send initialization code until seeing the prompt to ensure that
+      ;; the interpreter is ready.
+      ;; (while (not (valeri-prompt-line))
+       ;;  (accept-process-output (get-buffer-process (current-buffer)))
+        ;; (goto-char (point-max)))
+      ;; (valeri-send-string valeri-process-init-code)
+      ))
+
+  ;; when called interactively, switch to process buffer
+  (if (called-interactively-p 'any)
+      (switch-to-buffer valeri-process-buffer)))
+
+(defun valeri-prompt-line ()
+  (save-excursion
+    (save-match-data
+      (forward-line 0)
+      (if (looking-at comint-prompt-regexp)
+          (match-end 0)))))
+
+
+(provide 'valeri-mode)
+
+;;; valeri-mode.el ends here