diff --git a/t/gitweb-lib.sh b/t/gitweb-lib.sh
index 8cf909a6c..d5dab5a94 100644
--- a/t/gitweb-lib.sh
+++ b/t/gitweb-lib.sh
@@ -1,4 +1,5 @@
-#!/bin/sh
+# Initialization and helpers for Gitweb tests, which source this
+# shell library instead of test-lib.sh.
 #
 # Copyright (c) 2007 Jakub Narebski
 #
diff --git a/t/lib-bash.sh b/t/lib-bash.sh
index 11397f747..2be955faf 100644
--- a/t/lib-bash.sh
+++ b/t/lib-bash.sh
@@ -1,7 +1,6 @@
-#!/bin/sh
-#
-# Ensures that tests are run under Bash; primarily intended for running tests
-# of the completion script.
+# Shell library sourced instead of ./test-lib.sh by tests that need
+# to run under Bash; primarily intended for tests of the completion
+# script.
 
 if test -n "$BASH" && test -z "$POSIXLY_CORRECT"; then
 	# we are in full-on bash mode
diff --git a/t/lib-cvs.sh b/t/lib-cvs.sh
index 44263ade2..507671891 100644
--- a/t/lib-cvs.sh
+++ b/t/lib-cvs.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+# Shell library sourced instead of ./test-lib.sh by cvsimport tests.
 
 . ./test-lib.sh
 
diff --git a/t/lib-diff-alternative.sh b/t/lib-diff-alternative.sh
index 75ffd9174..8b4dbf22d 100644
--- a/t/lib-diff-alternative.sh
+++ b/t/lib-diff-alternative.sh
@@ -1,4 +1,5 @@
-#!/bin/sh
+# Helpers shared by the test scripts for diff algorithms (patience,
+# histogram, etc).
 
 test_diff_frobnitz() {
 	cat >file1 <<\EOF
diff --git a/t/lib-gettext.sh b/t/lib-gettext.sh
index ae8883a07..eec757f10 100644
--- a/t/lib-gettext.sh
+++ b/t/lib-gettext.sh
@@ -1,4 +1,5 @@
-#!/bin/sh
+# Initialization and Icelandic locale for basic git i18n tests,
+# which source this scriptlet instead of ./test-lib.sh.
 #
 # Copyright (c) 2010 Ævar Arnfjörð Bjarmason
 #
diff --git a/t/lib-git-daemon.sh b/t/lib-git-daemon.sh
index 87f0ad8f4..394b06b32 100644
--- a/t/lib-git-daemon.sh
+++ b/t/lib-git-daemon.sh
@@ -1,4 +1,20 @@
-#!/bin/sh
+# Shell library to run git-daemon in tests.  Ends the test early if
+# GIT_TEST_GIT_DAEMON is not set.
+#
+# Usage:
+#
+#	. ./test-lib.sh
+#	. "$TEST_DIRECTORY"/lib-git-daemon.sh
+#	start_git_daemon
+#
+#	test_expect_success '...' '
+#		...
+#	'
+#
+#	test_expect_success ...
+#
+#	stop_git_daemon
+#	test_done
 
 if test -z "$GIT_TEST_GIT_DAEMON"
 then
diff --git a/t/lib-httpd.sh b/t/lib-httpd.sh
index ad8f1ef71..c4707843c 100644
--- a/t/lib-httpd.sh
+++ b/t/lib-httpd.sh
@@ -1,4 +1,31 @@
-#!/bin/sh
+# Shell library to run an HTTP server for use in tests.
+# Ends the test early if httpd tests should not be run,
+# for example because the user has not enabled them.
+#
+# Usage:
+#
+#	. ./test-lib.sh
+#	. "$TEST_DIRECTORY"/lib-httpd.sh
+#	start_httpd
+#
+#	test_expect_success '...' '
+#		...
+#	'
+#
+#	test_expect_success ...
+#
+#	stop_httpd
+#	test_done
+#
+# Can be configured using the following variables.
+#
+#    GIT_TEST_HTTPD              enable HTTPD tests
+#    LIB_HTTPD_PATH              web server path
+#    LIB_HTTPD_MODULE_PATH       web server modules path
+#    LIB_HTTPD_PORT              listening port
+#    LIB_HTTPD_DAV               enable DAV
+#    LIB_HTTPD_SVN               enable SVN
+#    LIB_HTTPD_SSL               enable SSL
 #
 # Copyright (c) 2008 Clemens Buchacher <drizzd@aon.at>
 #
diff --git a/t/lib-pack.sh b/t/lib-pack.sh
index b96e1254d..750984657 100644
--- a/t/lib-pack.sh
+++ b/t/lib-pack.sh
@@ -1,5 +1,3 @@
-#!/bin/sh
-#
 # Support routines for hand-crafting weird or malicious packs.
 #
 # You can make a complete pack like:
diff --git a/t/lib-pager.sh b/t/lib-pager.sh
index ba03eab14..3aa7a3ffd 100644
--- a/t/lib-pager.sh
+++ b/t/lib-pager.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+# Helpers for tests of git's choice of pager.
 
 test_expect_success 'determine default pager' '
 	test_might_fail git config --unset core.pager &&
diff --git a/t/lib-read-tree.sh b/t/lib-read-tree.sh
index abc2c6f57..6442ae337 100644
--- a/t/lib-read-tree.sh
+++ b/t/lib-read-tree.sh
@@ -1,5 +1,3 @@
-#!/bin/sh
-#
 # Helper functions to check if read-tree would succeed/fail as expected with
 # and without the dry-run option. They also test that the dry-run does not
 # write the index and that together with -u it doesn't touch the work tree.
diff --git a/t/lib-rebase.sh b/t/lib-rebase.sh
index 8ff87fb3f..6bd252212 100644
--- a/t/lib-rebase.sh
+++ b/t/lib-rebase.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+# Helper functions used by interactive rebase tests.
 
 # After setting the fake editor with this function, you can
 #
diff --git a/t/lib-terminal.sh b/t/lib-terminal.sh
index 737df289a..9a2dca506 100644
--- a/t/lib-terminal.sh
+++ b/t/lib-terminal.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+# Helpers for terminal output tests.
 
 test_expect_success PERL 'set up terminal for tests' '
 	# Reading from the pty master seems to get stuck _sometimes_
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index f4eecaa17..a8c957429 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -1,4 +1,6 @@
-#!/bin/sh
+# Performance testing framework.  Each perf script starts much like
+# a normal test script, except it sources this library instead of
+# test-lib.sh.  See t/perf/README for documentation.
 #
 # Copyright (c) 2011 Thomas Rast
 #
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 2f79146e6..aeae3ca76 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -1,4 +1,5 @@
-#!/bin/sh
+# Library of functions shared by all tests scripts, included by
+# test-lib.sh.
 #
 # Copyright (c) 2005 Junio C Hamano
 #
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 596815704..c306bd066 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+# Test framework for git.  See t/README for usage.
 #
 # Copyright (c) 2005 Junio C Hamano
 #