diff --git a/interop/diff_genesis_vs_lighthouse.sh b/interop/diff_genesis_vs_lighthouse.sh
new file mode 100755
index 000000000..c23e4cb51
--- /dev/null
+++ b/interop/diff_genesis_vs_lighthouse.sh
@@ -0,0 +1,10 @@
+#!/bin/bash
+
+# Lighthouse genesis state
+curl localhost:5052/beacon/state?slot=0 | python -m json.tool | sed 's/"0x/"/' > /tmp/lighthouse_state.json
+
+# Format nimbus the same
+cat data/state_snapshot.json | python -m json.tool | sed 's/"0x/"/' > /tmp/nimbus_state.json
+
+diff -uw /tmp/nimbus_state.json /tmp/lighthouse_state.json
+
diff --git a/interop/diff_genesis_vs_zcli.sh b/interop/diff_genesis_vs_zcli.sh
new file mode 100755
index 000000000..8e08bf7f1
--- /dev/null
+++ b/interop/diff_genesis_vs_zcli.sh
@@ -0,0 +1,34 @@
+#!/bin/bash
+
+ETH2_PM=${ETH2_PM_PATH:-"eth2.0-pm"}
+
+set -eu
+
+echo Locating zcli...
+if ! command -v zcli; then
+  go get -tags preset_minimal github.com/protolambda/zcli
+fi
+
+if [[ ! -d "$ETH2_PM" ]]; then
+  git clone https://github.com/ethereum/eth2.0-pm "$ETH2_PM"
+fi
+
+# Fetch genesis time, as set up by start.sh
+if command -v jq; then
+  # requires the jq package for json parsing
+  genesis_time=$(jq '.genesis_time' data/state_snapshot.json)
+else
+  # grep -P for perl parsing, not available on Mac
+  genesis_time=$(grep -oP '(?<=genesis_time": )\w+(?=,)' data/state_snapshot.json)
+fi
+
+echo Genesis time was $genesis_time
+
+zcli genesis mock \
+  --count 16 \
+  --genesis-time $genesis_time \
+  --keys "${ETH2_PM}/interop/mocked_start/keygen_10000_validators.yaml" \
+  --out data/zcli_genesis.ssz
+
+zcli diff state data/zcli_genesis.ssz data/state_snapshot.ssz
+
diff --git a/interop/run_lighthouse.sh b/interop/run_lighthouse.sh
index 2566de0df..c3c578214 100755
--- a/interop/run_lighthouse.sh
+++ b/interop/run_lighthouse.sh
@@ -5,21 +5,58 @@
 
 # https://github.com/sigp/lighthouse/blob/master/docs/interop.md
 
+set -eu
+
+echo Locating protoc...
+if ! command -v protoc; then
+  MSG="protoc (the Google Protobuf compiler) is missing. Please install it manually"
+  if [[ "$OSTYPE" == "linux-gnu" ]]; then
+    MSG+=" with sudo apt install protobuf-compiler"
+  elif [[ "$OSTYPE" == "darwin"* ]]; then
+    MSG+=" with 'brew install protobuf'"
+  elif [[ "$OSTYPE" == "cygwin" ]]; then
+    # POSIX compatibility layer and Linux environment emulation for Windows
+    MSG+=""
+  elif [[ "$OSTYPE" == "msys" ]]; then
+    # Lightweight shell and GNU utilities compiled for Windows (part of MinGW)
+    MSG+=""
+  elif [[ "$OSTYPE" == "win32" ]]; then
+    # I'm not sure this can happen.
+    MSG+=""
+  elif [[ "$OSTYPE" == "freebsd"* ]]; then
+    # ...
+    MSG+=""
+  else
+    # Unknown.
+    MSG+=""
+  fi
+  echo $MSG
+  exit 1
+fi
+
 cargo_path=$(which cargo)
 [[ -x "$cargo_path" ]] || { echo "install rust first (https://rust-lang.org)"; exit 1; }
 
-[[ -d "lighthouse" ]] || {
-  git clone https://github.com/sigp/lighthouse.git
-  cd lighthouse
+LIGHTHOUSE=${LIGHTHOSE_PATH:-"lighthouse"}
+
+[[ -d "$LIGHTHOUSE" ]] || {
+  git clone https://github.com/sigp/lighthouse.git "$LIGHTHOUSE"
+  pushd "$LIGHTHOUSE"
   git checkout interop # temporary interop branch - will get merged soon I expect!
   cargo update
-  cd ..
+  popd
 }
 
 # Fetch genesis time, as set up by start.sh
-genesis_time=$(grep -oP '(?<=genesis_time": )\w+(?=,)' data/state_snapshot.json)
+if command -v jq; then
+  genesis_time=$(jq '.genesis_time' data/state_snapshot.json)
+else
+  genesis_time=$(grep -oP '(?<=genesis_time": )\w+(?=,)' data/state_snapshot.json)
+fi
 
-cd lighthouse
+echo Genesis time was $genesis_time
+
+cd "$LIGHTHOUSE"
 cargo build
 
 cd target/debug