diff --git a/tools/build.sh b/tools/build.sh
index fe3be4b..6b73dba 100755
--- a/tools/build.sh
+++ b/tools/build.sh
@@ -1,18 +1,18 @@
 #!/bin/bash -e
-home=`dirname $0`
+home=$(dirname $0)
 cd $home
 if [ -f buildpid.log ]; then
-	buildpid=`cat buildpid.log`
+	buildpid=$(cat buildpid.log)
 	kill -9 $buildpid || true
 	rm -f buildpid.log
 fi
 echo $$ > buildpid.log
 if [ -f nodepid.log ]; then
-	nodepid=`cat nodepid.log`
+	nodepid=$(cat nodepid.log)
 	kill -9 $nodepid || true
 	rm -f nodepid.log
 fi
-ver=`grep 'numeric.version.*=.*"' ../src/numeric.js | sed 's/numeric.version[ =]*"\([0-9.]*\)".*/\1/'`
+ver=$(grep 'numeric.version.*=.*"' ../src/numeric.js | sed 's/numeric.version[ =]*"\([0-9.]*\)".*/\1/')
 echo "Version is $ver"
 cat ../src/numeric.js ../src/seedrandom.js ../src/quadprog.js ../src/svd.js > ../lib/numeric-$ver.js
 uglifyjs ../lib/numeric-$ver.js > ../lib/numeric-$ver.min.js
@@ -44,7 +44,7 @@ cp ../src/documentation.html ..
 rm -f ../workshop.php
 sed -e '/WORKSHOPHTML/r workshop.html' -e 's/WORKSHOPHTML//' -e "s/VERSIONSTRING/$ver/" workshop_in.php > ../workshop.php
 cd ..
-runjs=`which d8 || which jsdb || which node`
+runjs=$(which d8 || which jsdb || which node)
 echo Using $runjs
 $runjs ./tools/unit2.js &
 echo $! > tools/nodepid.log
diff --git a/tools/deploy/#deploy.sh# b/tools/deploy/#deploy.sh#
index eab81b6..f3852eb 100755
--- a/tools/deploy/#deploy.sh#
+++ b/tools/deploy/#deploy.sh#
@@ -1,20 +1,20 @@
 #!/bin/bash
 set -e
-cd `dirname $0`
+cd $(dirname $0)
 cd ../..
-foo=`git status --porcelain` && 
+foo=$(git status --porcelain) && 
 if [ "x" != "x$foo" ]; then
     echo "Cannot deploy while there are uncommited changes."
     exit
 fi
-ver=`grep "numeric.version =" src/numeric.js | sed 's/.*[''"]\([0-9.]*\)[''"].*/\1/'`
+ver=$(grep "numeric.version =" src/numeric.js | sed 's/.*[''"]\([0-9.]*\)[''"].*/\1/')
 npm publish ./lib/numeric-1.1.9.tar.gz
 git tag v$ver
 git push --tags
 chmod a-w lib/numeric-$ver*.js
 cd tools/deploy
 source config.sh
-echo Fetching staging copy...
+echo "Fetching staging copy..."
 curl $server/staging/ > staging-copy.html
 if grep Loisel staging-copy.html > /dev/null; then
     echo "Fetched."
@@ -22,18 +22,18 @@ else
     echo "Staging copy does not work!"
     exit 1
 fi
-echo Deploying...
+echo "Deploying..."
 ssh $server -l $user "( cd $webroot && [ -L staging ] && foo=\`readlink staging\` && rm -f numeric && ln -s \$foo numeric && rm -f staging && numeric/tools/deploy/clean.sh && echo Deployment successful. ) || echo FAIL: Deployment unsuccessful."
-echo Comparing staging copy with live copy...
+echo "Comparing staging copy with live copy..."
 curl http://$server/ > live-copy.html
 if diff staging-copy.html live-copy.html >/dev/null; then
-    echo Staging and live copies match.
+    echo "Staging and live copies match."
 else
-    echo FAIL: Staging and live copies do not match.
+    echo "FAIL: Staging and live copies do not match."
     exit 1
 fi
 rm -f staging-copy.html live-copy.html
-echo Testing live links
+echo "Testing live links"
 cd ..
 pwd
 python ./selenium_links.py Firefox http://$server/
diff --git a/tools/deploy/clean.sh b/tools/deploy/clean.sh
index f8e3db2..c6fb6b5 100755
--- a/tools/deploy/clean.sh
+++ b/tools/deploy/clean.sh
@@ -1,11 +1,11 @@
 #!/bin/bash
 set -e
-cd `dirname $0`
+cd $(dirname $0)
 cd ../../..
-numeric=`readlink numeric || echo ""`
-staging=`readlink staging || echo ""`
+numeric=$(readlink numeric || echo "")
+staging=$(readlink staging || echo "")
 for x in v*; do
-    if [ "z$x" != "z$numeric" -a "z$x" != "z$staging" ]; then
+    if [ "z$x" != "z$numeric" ] && [ "z$x" != "z$staging" ]; then
 	rm -rf $x
     fi
 done
diff --git a/tools/deploy/deploy.sh b/tools/deploy/deploy.sh
index e4c5c10..b894d37 100755
--- a/tools/deploy/deploy.sh
+++ b/tools/deploy/deploy.sh
@@ -1,20 +1,20 @@
 #!/bin/bash
 set -e
-cd `dirname $0`
+cd $(dirname $0)
 cd ../..
-foo=`git status --porcelain` && 
+foo=$(git status --porcelain) && 
 if [ "x" != "x$foo" ]; then
     echo "Cannot deploy while there are uncommited changes."
     exit
 fi
-ver=`grep "numeric.version =" src/numeric.js | sed 's/.*[''"]\([0-9.]*\)[''"].*/\1/'`
+ver=$(grep "numeric.version =" src/numeric.js | sed 's/.*[''"]\([0-9.]*\)[''"].*/\1/')
 npm publish ./lib/numeric-$ver.tar.gz
 git tag v$ver
 git push --tags
 chmod a-w lib/numeric-$ver*.js
 cd tools/deploy
 source config.sh
-echo Fetching staging copy...
+echo "Fetching staging copy..."
 curl $server/staging/ > staging-copy.html
 if grep Loisel staging-copy.html > /dev/null; then
     echo "Fetched."
@@ -22,18 +22,18 @@ else
     echo "Staging copy does not work!"
     exit 1
 fi
-echo Deploying...
+echo "Deploying..."
 ssh $server -l $user "( cd $webroot && [ -L staging ] && foo=\`readlink staging\` && rm -f numeric && ln -s \$foo numeric && rm -f staging && numeric/tools/deploy/clean.sh && echo Deployment successful. ) || echo FAIL: Deployment unsuccessful."
-echo Comparing staging copy with live copy...
+echo "Comparing staging copy with live copy..."
 curl http://$server/ > live-copy.html
 if diff staging-copy.html live-copy.html >/dev/null; then
-    echo Staging and live copies match.
+    echo "Staging and live copies match."
 else
-    echo FAIL: Staging and live copies do not match.
+    echo "FAIL: Staging and live copies do not match."
     exit 1
 fi
 rm -f staging-copy.html live-copy.html
-echo Testing live links
+echo "Testing live links"
 cd ..
 pwd
 python ./selenium_links.py Firefox http://$server/
diff --git a/tools/deploy/stage.sh b/tools/deploy/stage.sh
index d543cff..b1f2a03 100755
--- a/tools/deploy/stage.sh
+++ b/tools/deploy/stage.sh
@@ -1,13 +1,13 @@
 #!/bin/bash
 set -e
-version=`date "+%Y-%m-%d_%H-%M-%S"`
-cd `dirname $0`
+version=$(date "+%Y-%m-%d_%H-%M-%S")
+cd $(dirname $0)
 rm -f version.txt
 echo $version > version.txt
 source config.sh
 cd ../../
-ver=`grep "numeric.version =" src/numeric.js | sed 's/.*[''"]\([0-9.]*\)[''"].*/\1/'`
-foo=`git tag -l v$ver`
+ver=$(grep "numeric.version =" src/numeric.js | sed 's/.*[''"]\([0-9.]*\)[''"].*/\1/')
+foo=$(git tag -l v$ver)
 if [ "x$foo" != "x" ]; then
     echo "The version $ver already exists."
     echo "You must update the version number in numeric.js."
diff --git a/tools/deploy/test.sh b/tools/deploy/test.sh
index 37c818e..83d68a5 100755
--- a/tools/deploy/test.sh
+++ b/tools/deploy/test.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
-cd `dirname $0`
+cd $(dirname $0) || exit 1
 source config.sh
-version=`cat version.txt`
+version=$(cat version.txt)
 rm -f wintests.log mactests.txt
 echo "test.sh: launching IE unit tests"
 cd ..
@@ -24,6 +24,6 @@ echo "test.sh: Mac/Firefox unit tests on $server/staging"
 python -u selenium_tests.py Firefox http://$server/staging/ >> $logfile 2>&1
 kill -9 $tailpid
 echo "test.sh: making report"
-cd deploy
+cd deploy || exit 1
 python make_report.py $version > report.html
 scp report.html $user@$server:$webroot/staging
diff --git a/tools/mkdoc.sh b/tools/mkdoc.sh
index c58419e..b06da9e 100755
--- a/tools/mkdoc.sh
+++ b/tools/mkdoc.sh
@@ -1,11 +1,11 @@
 #!/bin/bash
-d0=`dirname $0`
-d1=`cd $d0/.. && pwd`
+d0=$(dirname $0)
+d1=$(cd $d0/.. && pwd)
 djsdoc=$d1/tools/jsdoc-toolkit
 djs=$d1/lib
 ddoc=$d1/doc
 
-cd $djsdoc
+cd $djsdoc || exit 1
 echo "JSDoc:"
 rm -rf $ddoc
 mkdir $ddoc