diff --git a/Makefile b/Makefile
index c60cad1..ac1c05b 100644
--- a/Makefile
+++ b/Makefile
@@ -412,16 +412,16 @@
 # This runs an install from v.io, then runs the tutorials against that install,
 # exactly as an external user would run them. Local changes of Vanadium have no
 # impact on this test. This test does not require definition of JIRI_ROOT; it
-# uses V23_RELEASE instead, per the installation instructions on the external
+# uses VANADIUM_RELEASE instead, per the installation instructions on the external
 # site.
 .PHONY: test-tutorials-external
 test-tutorials-external: build
 	$(MDRIP) --subshell --blockTimeOut 10m test content/$(install_md) $(depsOneBigCoreTutorialTest)
 
-# Test tutorials without install. Assumes JIRI_ROOT and V23_RELEASE are defined.
+# Test tutorials without install. Assumes JIRI_ROOT and VANADIUM_RELEASE are defined.
 #
 # This runs tests without first doing any installation step, and assumes
-# JIRI_ROOT and V23_RELEASE are properly defined. It's a time saver if you are
+# JIRI_ROOT and VANADIUM_RELEASE are properly defined. It's a time saver if you are
 # happy with your installation and are just debugging tutorial code.
 .PHONY: test-tutorials-no-install
 test-tutorials-no-install: build
diff --git a/content/community/contributing.md b/content/community/contributing.md
index 0523240..e8e0f8f 100644
--- a/content/community/contributing.md
+++ b/content/community/contributing.md
@@ -19,7 +19,7 @@
 and have added `$JIRI_ROOT/.jiri_root/scripts` to your `PATH`:
 
     # Edit to taste.
-    export JIRI_ROOT=${HOME}/v23_root
+    export JIRI_ROOT=${HOME}/vanadium
     export PATH=$PATH:$JIRI_ROOT/.jiri_root/scripts
 
 Recommended: Add the lines above to your `~/.bashrc` or similar.
diff --git a/content/installation/index.md b/content/installation/index.md
index 3c299e7..f9279b5 100644
--- a/content/installation/index.md
+++ b/content/installation/index.md
@@ -32,14 +32,14 @@
 It runs all the steps from the [step-by-step instructions].
 
 In particular, it checks for prerequisites, sets the `JIRI_ROOT` and
-`V23_RELEASE` environment variables to `$HOME/v23_root` and
+`VANADIUM_RELEASE` environment variables to `$HOME/vanadium` and
 `$JIRI_ROOT/release/go` respectively, and installs Vanadium to the `JIRI_ROOT`
 directory using the `bootstrap.sh` script.
 
-The tutorials depend on `V23_RELEASE` to find the Vanadium installation, but
+The tutorials depend on `VANADIUM_RELEASE` to find the Vanadium installation, but
 Vanadium itself doesn't depend on this variable.
 
-Feel free to move `JIRI_ROOT` and `V23_RELEASE` elsewhere if you like.
+Feel free to move `JIRI_ROOT` and `VANADIUM_RELEASE` elsewhere if you like.
 
 [source]: /tutorials/faq.html#why-source-
 [tutorials]: /tutorials/hello-world.html
diff --git a/content/installation/step-by-step.md b/content/installation/step-by-step.md
index 721af9d..04a4c1c 100644
--- a/content/installation/step-by-step.md
+++ b/content/installation/step-by-step.md
@@ -47,38 +47,44 @@
 NFS are discouraged for performance reasons and to avoid git ENOKEY errors.)
 <!-- @define_JIRI_ROOT @test -->
 ```
-# Edit to taste.
-export JIRI_ROOT=${HOME}/v23_root
+# Uses existing $JIRI_ROOT environment variable, defaults to ${HOME}/vanadium if
+# $JIRI_ROOT is not set.
+export JIRI_ROOT=${JIRI_ROOT:=${HOME}/vanadium}
 ```
 
 Recommended for contributors: Add the line above to your `~/.bashrc` or similar.
 
-# V23_RELEASE environment variable
+# VANADIUM_RELEASE environment variable
 
 The tutorials on this website use Go code from a particular subdirectory of
-`JIRI_ROOT`. Tutorial users should set the `V23_RELEASE` environment variable to
+`JIRI_ROOT`. Tutorial users should set the `VANADIUM_RELEASE` environment variable to
 this directory, as follows:
-<!-- @define_V23_RELEASE @test -->
+<!-- @define_VANADIUM_RELEASE @test -->
 ```
 # Needed for tutorials only.
-export V23_RELEASE=${JIRI_ROOT}/release/go
+export VANADIUM_RELEASE=${JIRI_ROOT}/release/go
 ```
 
-# Start from a clean slate
+# Prompt for a clean slate
 
 The `bootstrap.sh` script checks that the `JIRI_ROOT` directory does not yet
-exist, then creates it. So, let's blow away `JIRI_ROOT` if it exists.
+exist, then creates it. If it exists, warn the user with a clear message about
+trying to install over an existing path and provide instructions on how to
+correct.
 
-{{# helpers.warning }}
-## Danger!
-This will blow away your `JIRI_ROOT` directory, including any pending changes to
-repositories in that directory. Make sure you're not deleting something
-important.
-{{/ helpers.warning }}
-<!-- @define_rmrf_JIRI_ROOT @test -->
+<!-- @check_JIRI_ROOT @test -->
 ```
-# WARNING: Make sure you're not deleting something important.
-rm -rf $JIRI_ROOT
+# Check that the JIRI_ROOT path does not exist.
+if [[ -e "${JIRI_ROOT}" ]]; then
+  echo ""
+  echo "ERROR: The JIRI_ROOT path already exists: ${JIRI_ROOT}"
+  echo "To proceed with a fresh install remove the directory and re-run:"
+  echo ""
+  echo "    rm -rf ${JIRI_ROOT}"
+  echo ""
+  echo "Or set JIRI_ROOT to a different path."
+  exit 1
+fi
 ```
 
 # Fetch Vanadium repositories
diff --git a/content/testing.md b/content/testing.md
index 6abd13a..0744d9d 100644
--- a/content/testing.md
+++ b/content/testing.md
@@ -44,7 +44,7 @@
 
 <!-- @defineLocalEnv @test @testui @buildjs -->
 ```
-export V23_RELEASE=${JIRI_ROOT}/release/go
+export VANADIUM_RELEASE=${JIRI_ROOT}/release/go
 
 # Extract GOPATH from jiri utility.
 export V23_GOPATH=`jiri go env GOPATH`
diff --git a/content/tutorials/basics.md b/content/tutorials/basics.md
index 2243fb8..62162b9 100644
--- a/content/tutorials/basics.md
+++ b/content/tutorials/basics.md
@@ -105,7 +105,7 @@
 
 <!-- @compileInterface @buildjs @test @testui @completer -->
 ```
-VDLROOT=$V23_RELEASE/src/v.io/v23/vdlroot \
+VDLROOT=$VANADIUM_RELEASE/src/v.io/v23/vdlroot \
     VDLPATH=$V_TUT/src \
     $V_BIN/vdl generate --lang go $V_TUT/src/fortune/ifc
 go build fortune/ifc
diff --git a/content/tutorials/checkup.md b/content/tutorials/checkup.md
index 610659a..8156d64 100644
--- a/content/tutorials/checkup.md
+++ b/content/tutorials/checkup.md
@@ -6,7 +6,7 @@
 enumerable: false
 = yaml =
 
-A smoke test to see that `V23_RELEASE` is defined and provides access to crucial
+A smoke test to see that `VANADIUM_RELEASE` is defined and provides access to crucial
 Vanadium file assets.
 
 This isn't meant to be an exhaustive test, just a quick check. It's used in
@@ -24,7 +24,7 @@
   exit 1;
 }
 
-[ -z "$V23_RELEASE" ] && { echo 'The environment variable V23_RELEASE is not defined.'; bad_vanadium; }
+[ -z "$VANADIUM_RELEASE" ] && { echo 'The environment variable VANADIUM_RELEASE is not defined.'; bad_vanadium; }
 
-[ -x "$V23_RELEASE/bin/principal" ] || { echo 'The file $V23_RELEASE/bin/principal does not exist or is not executable.'; bad_vanadium; }
+[ -x "$VANADIUM_RELEASE/bin/principal" ] || { echo 'The file $VANADIUM_RELEASE/bin/principal does not exist or is not executable.'; bad_vanadium; }
 ```
diff --git a/content/tutorials/hello-world.md b/content/tutorials/hello-world.md
index b88605d..82da7c1 100644
--- a/content/tutorials/hello-world.md
+++ b/content/tutorials/hello-world.md
@@ -60,7 +60,7 @@
 
 <!-- @compileInterface @test @completer -->
 ```
-VDLROOT=$V23_RELEASE/src/v.io/v23/vdlroot \
+VDLROOT=$VANADIUM_RELEASE/src/v.io/v23/vdlroot \
     VDLPATH=$V_TUT/src \
     $V_BIN/vdl generate --lang go $V_TUT/src/hello/ifc
 ```
diff --git a/content/tutorials/security/permissions-authorizer.md b/content/tutorials/security/permissions-authorizer.md
index 6d2fa90..d52dafa 100644
--- a/content/tutorials/security/permissions-authorizer.md
+++ b/content/tutorials/security/permissions-authorizer.md
@@ -54,7 +54,7 @@
 }
 EOF
 
-VDLROOT=$V23_RELEASE/src/v.io/v23/vdlroot \
+VDLROOT=$VANADIUM_RELEASE/src/v.io/v23/vdlroot \
     VDLPATH=$V_TUT/src \
     $V_BIN/vdl generate --lang go $V_TUT/src/fortune/ifc
 go build fortune/ifc
diff --git a/content/tutorials/setup.md b/content/tutorials/setup.md
index d692885..98e3c20 100644
--- a/content/tutorials/setup.md
+++ b/content/tutorials/setup.md
@@ -10,7 +10,7 @@
 start a second tutorial terminal, likely to keep the output from multiple
 processes easier to read.
 
-In addition to the `$V23_RELEASE` variable defined by [installation], every
+In addition to the `$VANADIUM_RELEASE` variable defined by [installation], every
 terminal window used in a tutorial must run the environment definition script
 below.
 
@@ -23,11 +23,11 @@
 
 <!-- @envVars @buildjs @test @testui @completer -->
 ```
-# If JIRI_ROOT or V23_RELEASE are not defined, set them to the default values
+# If JIRI_ROOT or VANADIUM_RELEASE are not defined, set them to the default values
 # from the installation instructions and hope for the best.
 
-[ -z "$JIRI_ROOT" ] && export JIRI_ROOT=${HOME}/v23_root
-[ -z "$V23_RELEASE" ] && export V23_RELEASE=${JIRI_ROOT}/release/go
+[ -z "$JIRI_ROOT" ] && export JIRI_ROOT=${HOME}/vanadium
+[ -z "$VANADIUM_RELEASE" ] && export VANADIUM_RELEASE=${JIRI_ROOT}/release/go
 
 # All files created by the tutorial will be placed in $V_TUT. It is a disposable
 # workspace, easy to recreate.
@@ -36,7 +36,7 @@
 # V_BIN is a convenience for running Vanadium binaries. It avoids the need to
 # modify your PATH or to be 'in' a particular directory when doing the
 # tutorials.
-export V_BIN=${V23_RELEASE}/bin
+export V_BIN=${VANADIUM_RELEASE}/bin
 
 # For the shell doing the tutorials, GOPATH must include both Vanadium and the
 # code created as a result of doing the tutorials. To avoid trouble with