diff --git a/scripts/install/install_rhel-derivs.sh b/scripts/install/install_rhel-derivs.sh
index 8c856ba40f..b5abfbdd25 100755
--- a/scripts/install/install_rhel-derivs.sh
+++ b/scripts/install/install_rhel-derivs.sh
@@ -117,13 +117,6 @@ fi
 
 confirm
 
-if [[ ! -e libphutil ]]
-then
-  git clone https://github.com/phacility/libphutil.git
-else
-  (cd libphutil && git pull --rebase)
-fi
-
 if [[ ! -e arcanist ]]
 then
   git clone https://github.com/phacility/arcanist.git
diff --git a/scripts/install/install_ubuntu.sh b/scripts/install/install_ubuntu.sh
index ab83c3a46c..7f5f552fdf 100755
--- a/scripts/install/install_ubuntu.sh
+++ b/scripts/install/install_ubuntu.sh
@@ -93,12 +93,6 @@ sudo a2enmod rewrite  || failed
 
 echo "Downloading Phabricator and dependencies..."
 echo
-if [ ! -e libphutil ]
-then
-  git clone https://github.com/phacility/libphutil.git
-else
-  (cd libphutil && git pull --rebase)
-fi
 
 if [ ! -e arcanist ]
 then
diff --git a/src/docs/user/installation_guide.diviner b/src/docs/user/installation_guide.diviner
index 29895eb2a9..269b20b62a 100644
--- a/src/docs/user/installation_guide.diviner
+++ b/src/docs/user/installation_guide.diviner
@@ -64,13 +64,14 @@ Beyond an operating system, you will need **a webserver**.
     works fine.
   - **Other**: Other webservers which can run PHP are also likely to work fine,
     although these installation instructions will not cover how to set them up.
-  - **PHP Builtin Server**: You can use the builtin PHP webserver for
-    development or testing, although it should not be used in production.
+  - **PHP Builtin Server**: Phabricator will not work with the builtin
+    webserver because Phabricator depends on making requests to itself on some
+    workflows, and the builtin webserver is single-threaded.
 
 You will also need:
 
   - **MySQL**: You need MySQL. We strongly recommend MySQL 5.5 or newer.
-  - **PHP**: You need PHP 5.2 or newer.
+  - **PHP**: You need PHP 5.5 or newer.
 
 You'll probably also need a **domain name**. In particular, you should read this
 note:
@@ -124,9 +125,7 @@ Otherwise, here's a general description of what you need to install:
   - PHP (usually "php")
   - Required PHP extensions: mbstring, iconv, mysql (or mysqli), curl, pcntl
     (these might be something like "php-mysql" or "php5-mysqlnd")
-  - Optional PHP extensions: gd, apc (special instructions for APC are available
-    below if you have difficulty installing it), xhprof (instructions below,
-    you only need this if you are developing Phabricator)
+  - Optional PHP extensions: gd
 
 If you already have LAMP setup, you've probably already got everything you need.
 It may also be helpful to refer to the install scripts above, even if they don't
@@ -136,41 +135,11 @@ Now that you have all that stuff installed, grab Phabricator and its
 dependencies:
 
   $ cd somewhere/ # pick some install directory
-  somewhere/ $ git clone https://github.com/phacility/libphutil.git
   somewhere/ $ git clone https://github.com/phacility/arcanist.git
   somewhere/ $ git clone https://github.com/phacility/phabricator.git
 
-= Installing APC (Optional) =
-
-Like everything else written in PHP, Phabricator will run much faster with APC
-installed. You likely need to install "pcre-devel" first:
-
-  sudo yum install pcre-devel
-
-Then you have two options. Either install via PECL (try this first):
-
-  sudo yum install php-pear
-  sudo pecl install apc
-
-**If that doesn't work**, grab the package from PECL directly and follow the
-build instructions there:
-
-http://pecl.php.net/package/APC
-
-Installing APC is optional but **strongly recommended**, especially on
-production hosts.
-
-Once APC is installed, test that it is available by running:
-
-  php -i | grep apc
-
-If it doesn't show up, add:
-
-  extension=apc.so
-
-..to "/etc/php.d/apc.ini" or the "php.ini" file indicated by "php -i".
-
-= Next Steps =
+Next Steps
+==========
 
 Continue by:
 
diff --git a/src/docs/user/upgrading.diviner b/src/docs/user/upgrading.diviner
index bf15aa5904..705b38e4ee 100644
--- a/src/docs/user/upgrading.diviner
+++ b/src/docs/user/upgrading.diviner
@@ -43,7 +43,6 @@ To switch to `stable`, check the branch out in each working copy:
 
   phabricator/ $ git checkout stable
   arcanist/ $ git checkout stable
-  libphutil/ $ git checkout stable
 
 You can now follow the upgrade process normally.
 
@@ -54,8 +53,7 @@ Upgrade Process
 IMPORTANT: You **MUST** restart Phabricator after upgrading. For help, see
 @{article:Restarting Phabricator}.
 
-IMPORTANT: You **MUST** upgrade `libphutil`, `arcanist` and `phabricator` at
-the same time.
+IMPORTANT: You **MUST** upgrade `arcanist` and `phabricator` at the same time.
 
 Phabricator runs on many different systems, with many different webservers.
 Given this diversity, we don't currently maintain a comprehensive upgrade
@@ -64,7 +62,7 @@ on every system:
 
   - Stop the webserver (including `php-fpm`, if you use it).
   - Stop the daemons, with `phabricator/bin/phd stop`.
-  - Run `git pull` in `libphutil/`, `arcanist/` and `phabricator/`.
+  - Run `git pull` in `arcanist/` and `phabricator/`.
   - Run `phabricator/bin/storage upgrade`.
   - Start the daemons, with `phabricator/bin/phd start`.
   - Restart the webserver (and `php-fpm`, if you stopped it earlier).
@@ -86,7 +84,7 @@ set -x
 # to work without modifications.
 
 # NOTE: This script assumes you are running it from a directory which contains
-# arcanist/, libphutil/, and phabricator/.
+# arcanist/, and phabricator/.
 
 ROOT=`pwd` # You can hard-code the path here instead.
 
@@ -107,9 +105,6 @@ sudo /etc/init.d/httpd stop
 
 ### UPDATE WORKING COPIES ######################################################
 
-cd $ROOT/libphutil
-git pull
-
 cd $ROOT/arcanist
 git pull