diff --git a/debugger.lua b/debugger.lua
index e54bc5c..8cf7e93 100644
--- a/debugger.lua
+++ b/debugger.lua
@@ -2,72 +2,113 @@ local core = require "core"
 
 ---@class runner
 local runner = {
-  new = function(self, o) end, ---@meta
+  new = function(self, o)
+    o = o or {}
+    setmetatable(o, self)
+    self.__index = self
+    return o
+  end,
+
+  caps = {
+    can_pause = false,
+    can_continue = false,
+    can_step_in = false,
+    can_step_over = false,
+    can_step_out = false,
+    can_breakpoints = false,
+    has_stack = false,
+    has_locals = false,
+    can_eval = false,
+  },
+
   run = function(self, target, name) end,  ---@meta
-  wait = function(sefl, time) end,  ---@meta 
+  pause = function(self) end, --@meta
+  continue = function(self) end, --@meta
+  step_in = function(self) end, --@meta
+  step_over = function(self) end, --@meta
+  step_out = function(self) end, --@meta
+
+  wait = function(self, time) end,  ---@meta 
   kill = function(self) end, ---@meta 
-  terminate = function(self) end, ---@meta 
+  terminate = function(self) end, ---@meta
+
+  -- Callbacks
+  log = function(msg) end, ---@meta
+  error = function(msg) end, ---@meta
+  on_stdout = function(msg) end, ---@meta
+  on_stderr = function(msg) end, ---@meta
+  on_exit = function(exitcode) end, ---@meta
+  on_state = function(state) end, ---@meta
+  on_break = function(file, line, reason) end, --@meta
+  on_stack = function(frames) end, ---@meta
+  on_locals = function(frame, vars) end, ---@meta
+  on_evaluated = function(expr, ok, value) end, ---@meta
 }
 
-local debugger = {}
-local debugwindow = nil ---@type JPDebugView
-local debugrunner = nil ---@type runner|nil
+local debugger = {
+  runner = runner, -- Set here as member to let runners extend this base class
+  debugwindow = nil, ---@type JPDebugView
+  debugrunner = nil, ---@type runner|nil
+}
 
 function debugger.log(msg)
   core.log("[jpdebug][debugger] %s", msg)
-  if debugwindow then debugwindow:push("meta", "debugger] "..msg) end
+  if debugger.debugwindow then debugger.debugwindow:push("meta", "debugger] "..msg) end
 end
 
 function debugger.error(msg)
   core.error("[jpdebug][debugger]"..msg)
-  if debugwindow then debugwindow:push("meta", "debugger] ERROR: "..msg) end
+  if debugger.debugwindow then debugger.debugwindow:push("meta", "debugger] ERROR: "..msg) end
 end
 
-function debugger.stdout(msg)
-  if debugwindow then debugwindow:push("stdout", msg) end
+function debugger.on_stdout(msg)
+  if debugger.debugwindow then debugger.debugwindow:push("stdout", msg) end
 end
 
-function debugger.stderr(msg)
-  if debugwindow then debugwindow:push("stderr", msg) end
+function debugger.on_stderr(msg)
+  if debugger.debugwindow then debugger.debugwindow:push("stderr", msg) end
 end
 
 function debugger.is_running()
-  return debugrunner~=nil
+  return debugger.debugrunner~=nil
 end
 
 function debugger.run(target, name, r, view)
-  debugwindow = view
-  debugwindow:clear()
+  if debugger.debugrunner then
+    debugger.error("Already an active session")
+    return
+  end
+  debugger.debugwindow = view
+  debugger.debugwindow:clear()
   debugger.log(string.format("Running %s", name))
 
   -- Create new runner object
-  debugrunner = r:new({
+  debugger.debugrunner = r:new({
+    -- Set callbacks
     log = debugger.log,
     error = debugger.error,
-    stdout = debugger.stdout,
-    stderr = debugger.stderr,
-    exited = debugger.exited,
+    on_stdout = debugger.on_stdout,
+    on_stderr = debugger.on_stderr,
+    on_exit = debugger.on_exit,
   })
   -- And run
-  debugrunner:run(target, name)
+  debugger.debugrunner:run(target, name)
 end
 
 function debugger.stop()
-  if debugrunner then
-    debugrunner:kill()
-    local exitcode = debugrunner:wait(1000)
+  if debugger.debugrunner then
+    debugger.debugrunner.on_exit = function() end
+    debugger.debugrunner:kill()
+    local exitcode = debugger.debugrunner:wait(1000)
     -- TODO terminate if needed
-    debugger.log(string.format("... Stoped: %d", exitcode))
+    debugger.log(string.format("... Stoped with exit code %d", exitcode))
   end
-  debugrunner = nil
+  debugger.debugrunner = nil
 end
 
-function debugger.exited()
-  if debugrunner then
-    local exitcode = debugrunner:wait(process.WAIT_INFINITE)
-    debugger.log(string.format("exit: %d", exitcode))
-  end
-  debugrunner = nil
+function debugger.on_exit(exitcode)
+  debugger.log(string.format("exit: %d", exitcode))
+  debugger.debugrunner = nil
 end
 
 return debugger
diff --git a/init.lua b/init.lua
index abf669e..1e4d32c 100644
--- a/init.lua
+++ b/init.lua
@@ -233,6 +233,11 @@ if required_toolbar_plugins and ToolbarView then
     else
       table.insert(t, {symbol = "D", command = "jpdebug:stop"})
     end
+
+    if debugger.is_running() then
+      if debugger.debugrunner.caps.can_pause then table.insert(t, {symbol="C",command=""}) end
+    end
+    
     table.insert(t, {symbol = "E", command = "jpdebug:reload-runners"})
     self.toolbar_commands = t
   end
diff --git a/runners/luadebug.lua b/runners/luadebug.lua
index c38dfb4..8a11454 100644
--- a/runners/luadebug.lua
+++ b/runners/luadebug.lua
@@ -1,5 +1,12 @@
 local core = require "core"
 local process = require "process"
+local debugger = require "plugins.jpdebug.debugger"
+
+---@class luadebug: runner
+local luadebug = debugger.runner:new({
+  name = "luadebug",
+  proc = nil ---@type process|nil
+})
 
 -- tiny helpers
 local function dirname(p) return p:match("^(.*)[/\\]") or "" end
@@ -53,18 +60,44 @@ local function spawn_lua_process(entry, lua, cwd, env)
   return proc
 end
 
----@class LDB
-local LDB = {
-  name = "luadebug"
-}
+local function spawn_mdb_process(lua)
+  local vendor_glob = join(get_plugin_root(), "vendor/?.lua")
+  local cmd = {}
+   if type(lua) == "table" then
+    for i=1, #lua do table.insert(cmd, lua[i]) end
+  else
+    table.insert(cmd, lua)
+  end
+  table.insert(cmd, "-e")
+  table.insert(cmd, string.format([[
+    package.path = %q .. ";" .. package.path
+    require("mobdebug").listen()
+  ]], vendor_glob))
+  local proc = process.start(cmd, {
+    stdout = process.REDIRECT_PIPE,
+    stderr = process.REDIRECT_PIPE,
+  })
+  return proc
+end
 
----@param target table Target table
----@param name string Name of the target to run
----@praam debuginfo table Debugging information
----@return process|nil
-function LDB:run(target, name, debuginfo)
+function luadebug:mdb_pump()
+  while true do
+    core.redraw = true
+    coroutine.yield(0.016) -- 60FPS
+    local sout = self.mdb:read_stdout()
+    local serr = self.mdb:read_stderr()
+    if sout == nil and serr == nil then
+      -- mdb exited
+      break
+    end
+    if sout and sout~="" then self.on_stdout("mdb>"..sout) end
+    if serr and serr~="" then self.on_stdout("mdb> ERROR: "..serr) end
+  end
+end
+
+function luadebug:run(target, name)
   if target.entry == nil then
-    core.error("[jpdebug][luadebug] target.entry is required")
+    self.error("target.entry is required for "..name)
     return
   end
   local entry = target.entry
@@ -72,44 +105,70 @@ function LDB:run(target, name, debuginfo)
   local cwd = target.cwd or "."
   local env = target.env or {}
 
+  -- spwawn the mobdebug process
+  self.mdb = spawn_mdb_process(lua)
+  local dbg = self
+  core.add_thread(function()
+    luadebug.mdb_pump(dbg)
+  end)
+
   -- spawn the main lua process
   local proc = spawn_lua_process(entry, lua, cwd, env)
-
   if proc == nil then
-    core.error("[jpdebug][luadebug] Failed to start "..entry)
-    return nil
+    self.error("Failed to start "..entry)
+    return
   end
+  self.proc = proc
 
-  return {
-    luaproc=proc
-  }
+    -- output pump
+  core.add_thread(function()
+    while true do
+      core.redraw = true
+      coroutine.yield(0.016) -- 60FPS
+      local sout = self.proc:read_stdout()
+      local serr = self.proc:read_stderr()
+      if sout == nil and serr == nil then
+        local exitcode = self.proc:wait(process.WAIT_INFINITE)
+        self.on_exit(exitcode)
+        break
+      end
+      if sout and sout~="" then self.on_stdout(sout) end
+      if serr and serr~="" then self.on_stderr(serr) end
+    end
+  end)
 end
 
--- Wait untill it ends, possibly with timeout
-function LDB:wait(proc, time)
-  return proc.luaproc:wait(time)
+function luadebug:wait(time)
+  if not self.proc then return end
+  return self.proc:wait(time)
 end
 
--- Read the stdout, returns nil if process has stopped
-function LDB:read_stdout(proc)
-  local sl = proc.luaproc:read_stdout()
+function luadebug:read_stdout()
+  if not self.proc then return end
+  local sl = self.proc:read_stdout()
   return sl
 end
 
--- Read the stderr
-function LDB:read_stderr(proc)
-  local sl = proc.luaproc:read_stderr()
+function luadebug:read_stderr()
+  if not self.proc then return end
+  local sl = self.proc:read_stderr()
   return sl
 end
 
--- Kill the process
-function LDB:kill(proc)
-  proc.luaproc:kill()
+function luadebug:kill()
+  if self.mdb then
+    -- Execute ctrl-C twice to exit mobdebug
+    self.mdb:kill()
+    self.mdb:kill()
+  end
+  if not self.proc then return end
+  self.proc:kill()
 end
 
--- Terminate the process
-function LDB:terminate(proc)
-  proc.luaproc:terminate()
+function luadebug:terminate()
+  if not self.proc then return end
+  self.proc:terminate()
 end
 
-return LDB
+return luadebug
+
diff --git a/runners/shell.lua b/runners/shell.lua
index 8661531..1be232f 100644
--- a/runners/shell.lua
+++ b/runners/shell.lua
@@ -1,30 +1,12 @@
 local core = require "core"
 local process  = require "process"
+local debugger = require "plugins.jpdebug.debugger"
 
 ---@class shell: runner
-local shell = {
+local shell = debugger.runner:new({
   name = "shell",
   proc = nil ---@type process|nil
-}
-
-function shell:new(o)
-  o = o or {}
-  setmetatable(o, self)
-  self.__index = self
-  return o
-end
-
----@meta
-function shell.log(msg) end
----@meta
-function shell.error(msg) end
----@meta
-function shell.stdout(msg) end
----@meta
-function shell.stderr(msg) end
----@meta
-function shell.exited() end
-
+})
 
 function shell:run(target, name)
   local opts = {
@@ -51,11 +33,12 @@ function shell:run(target, name)
       local sout = self.proc:read_stdout()
       local serr = self.proc:read_stderr()
       if sout == nil and serr == nil then
-        self.exited()
+        local exitcode = self.proc:wait(process.WAIT_INFINITE)
+        self.on_exit(exitcode)
         break
       end
-      if sout and sout~="" then self.stdout(sout) end
-      if serr and serr~="" then self.stderr(serr) end
+      if sout and sout~="" then self.on_stdout(sout) end
+      if serr and serr~="" then self.on_stderr(serr) end
     end
   end)
 end