diff --git a/NAMESPACE b/NAMESPACE
index 114438c4..0bfe23c6 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -28,6 +28,7 @@ export(monty_model_gradient)
 export(monty_model_properties)
 export(monty_observer)
 export(monty_packer)
+export(monty_packer_grouped)
 export(monty_rng)
 export(monty_rng_distributed_pointer)
 export(monty_rng_distributed_state)
diff --git a/R/runner.R b/R/runner.R
index 38b2b162..b1bc9843 100644
--- a/R/runner.R
+++ b/R/runner.R
@@ -53,17 +53,17 @@ monty_runner_serial <- function(progress = NULL) {
 
 ##' Run MCMC chains in parallel (at the same time).  This runner uses
 ##' the `parallel` package to distribute your chains over a number of
-##' worker processes on the same machine.  Compared with the "worker"
-##' support in `mcstate` version 1 this is very simple and we'll improve
-##' it over time.  In particular we do not report back any information
-##' about progress while a chain is running on a worker or even across
-##' chains.  There's also no support to warn you if your number of
-##' chains do not neatly divide through by the number of workers.
-##' Mostly this exists as a proof of concept for us to think about the
-##' different interfaces.  Unless your chains are quite slow, the
-##' parallel runner will be slower than the serial runner
-##' ([monty_runner_serial]) due to the overhead cost of starting the
-##' cluster.
+##' worker processes on the same machine.  Compared with
+##' [monty_runner_callr] (Whch is similar to the "worker" support in
+##' `mcstate` version 1), this is very simple.  In particular we do
+##' not report back any information about progress while a chain is
+##' running on a worker or even across chains.  There's also no
+##' support to warn you if your number of chains do not neatly divide
+##' through by the number of workers.  Mostly this exists as a proof
+##' of concept for us to think about the different interfaces.  Unless
+##' your chains are quite slow, the parallel runner will be slower
+##' than the serial runner ([monty_runner_serial]) due to the overhead
+##' cost of starting the cluster.
 ##'
 ##' @title Run MCMC chain in parallel
 ##'
diff --git a/README.md b/README.md
index fc5b452c..4740e905 100644
--- a/README.md
+++ b/README.md
@@ -31,7 +31,6 @@ The [`odin2`](https://mrc-ide.github.io/odin2/) package can generate dynamical m
 
 The basic functionality of this package is in place, but we plan to do work on:
 
-* expanding runners to include parallel chains (a basic parallel runner exists, but we will port over the `callr`-based runner from `mcstate`)
 * improving debugging tools if models fail mid-chain
 * implementing parallel tempering, allowing you to compose with any other supported sampler
 * improving support for nested models
diff --git a/man/monty_packer.Rd b/man/monty_packer.Rd
index 89af6330..6755d3ca 100644
--- a/man/monty_packer.Rd
+++ b/man/monty_packer.Rd
@@ -182,7 +182,7 @@ machinery).
 
 The input to \code{pack()} will be the shape that \code{unpack()} returned;
 a named list of numerical vectors, matrices and arrays.  The names
-must correspond do the names if your packer (i.e., \code{scalar} and
+must correspond to the names in your packer (i.e., \code{scalar} and
 the names of \code{array}).  Each element has dimensions
 
 \if{html}{\out{<div class="sourceCode">}}\preformatted{<...object, ...residual>
diff --git a/man/monty_runner_parallel.Rd b/man/monty_runner_parallel.Rd
index bbc5a020..209cf25e 100644
--- a/man/monty_runner_parallel.Rd
+++ b/man/monty_runner_parallel.Rd
@@ -23,15 +23,15 @@ A runner of class \code{monty_runner} that can be passed to
 \description{
 Run MCMC chains in parallel (at the same time).  This runner uses
 the \code{parallel} package to distribute your chains over a number of
-worker processes on the same machine.  Compared with the "worker"
-support in \code{mcstate} version 1 this is very simple and we'll improve
-it over time.  In particular we do not report back any information
-about progress while a chain is running on a worker or even across
-chains.  There's also no support to warn you if your number of
-chains do not neatly divide through by the number of workers.
-Mostly this exists as a proof of concept for us to think about the
-different interfaces.  Unless your chains are quite slow, the
-parallel runner will be slower than the serial runner
-(\link{monty_runner_serial}) due to the overhead cost of starting the
-cluster.
+worker processes on the same machine.  Compared with
+\link{monty_runner_callr} (Whch is similar to the "worker" support in
+\code{mcstate} version 1), this is very simple.  In particular we do
+not report back any information about progress while a chain is
+running on a worker or even across chains.  There's also no
+support to warn you if your number of chains do not neatly divide
+through by the number of workers.  Mostly this exists as a proof
+of concept for us to think about the different interfaces.  Unless
+your chains are quite slow, the parallel runner will be slower
+than the serial runner (\link{monty_runner_serial}) due to the overhead
+cost of starting the cluster.
 }