diff --git a/Makefile.in b/Makefile.in
index e9cb42a..5c1c860 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -107,8 +107,8 @@ OBJS		=	\
 			testpdfio.o \
 			testttf.o
 TARGETS		=	\
-			$(DSONAME) \
-			libpdfio.a \
+			$(LIBPDFIO) \
+			$(LIBPDFIO_STATIC) \
 			pdfiototext \
 			testpdfio \
 			testttf
diff --git a/README.md b/README.md
index 37265d7..1f53887 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ PDFio requires the following to build the software:
 
 - A C99 compiler such as Clang, GCC, or MS Visual C
 - A POSIX-compliant `make` program
-- ZLIB (<https://www.zlib.net>) 1.0 or higher
+- ZLIB (<https://www.zlib.net>) 1.1 or higher
 
 IDE files for Xcode (macOS/iOS) and Visual Studio (Windows) are also provided.
 
@@ -36,15 +36,27 @@ IDE files for Xcode (macOS/iOS) and Visual Studio (Windows) are also provided.
 Documentation
 -------------
 
-See the man page (`pdfio.3`), frequently ask questions (`FAQ.md`), and full HTML
-documentation (`pdfio.html`) for information on using PDFio.
+See the man page (`pdfio.3`) and full HTML documentation (`pdfio.html`) for
+information on using PDFio.
 
 
-Installing pdfio
+Installing PDFio
 ----------------
 
-PDFio comes with a portable makefile that will work on any POSIX-compliant
-system with ZLIB installed.  To make it, run:
+PDFio uses a configure script on Unix systems to generate a makefile:
+
+    ./configure
+
+If you want a shared library, run:
+
+    ./configure --enable-shared
+
+The default installation location is "/usr/local".  Pass the `--prefix` option
+to make to install it to another location:
+
+    ./configure --prefix=/some/other/directory
+
+Once configured, run the following to make the library:
 
     make all
 
@@ -54,45 +66,7 @@ To test it, run:
 
 To install it, run:
 
-    make install
-
-If you want a shared library, run:
-
-    make all-shared
-    make install-shared
-
-The default installation location is "/usr/local".  Pass the `prefix` variable
-to make to install it to another location:
-
-    make install prefix=/some/other/directory
-
-The makefile installs the pdfio header to "${prefix}/include", the library to
-"${prefix}/lib", the `pkg-config` file to "${prefix}/lib/pkgconfig", the man
-page to "${prefix}/share/man/man3", and the documentation to
-"${prefix}/share/doc/pdfio".
-
-The makefile supports the following variables that can be specified in the make
-command or as environment variables:
-
-- `AR`: the library archiver (default "ar")
-- `ARFLAGS`: options for the library archiver (default "cr")
-- `CC`: the C compiler (default "cc")
-- `CFLAGS`: options for the C compiler (default "")
-- `CODESIGN_IDENTITY`: the identity to use when code signing the shared library
-  on macOS (default "Developer ID")
-- `COMMONFLAGS`: options for the C compiler and linker (typically architecture
-  and optimization options, default is "-Os -g")
-- `CPPFLAGS`: options for the C preprocessor (default "")
-- `DESTDIR` and `DSTROOT`: specifies a root directory when installing
-  (default is "", specify only one)
-- `DSOFLAGS`: options for the C compiler when linking the shared library
-  (default "")
-- `LDFLAGS`: options for the C compiler when linking the test programs
-  (default "")
-- `LIBS`: library options when linking the test programs (default "-lz")
-- `RANLIB`: program that generates a table-of-contents in a library
-  (default "ranlib")
-- `prefix`: specifies the installation directory (default "/usr/local")
+    sudo make install
 
 
 Visual Studio Project
@@ -111,10 +85,6 @@ generates a static library that will be installed under "/usr/local" with:
 
     sudo xcodebuild install
 
-You can reproduce this with the makefile using:
-
-    sudo make macos install
-
 
 Legal Stuff
 -----------
diff --git a/configure b/configure
index 24b8cf4..d1524a4 100755
--- a/configure
+++ b/configure
@@ -1368,7 +1368,7 @@ Optional Features:
   --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
   --disable-static        do not install static library
-  --disable-shared        do not install shared library
+  --enable-shared         install shared library
   --enable-debug          turn on debugging, default=no
   --enable-maintainer     turn on maintainer mode, default=no
   --enable-sanitizer      build with AddressSanitizer, default=no
@@ -4111,7 +4111,7 @@ then :
 fi
 
 
-if test x$enable_shared != xno
+if test x$enable_shared = xyes
 then :
 
     if test "$host_os_name" = darwin
diff --git a/configure.ac b/configure.ac
index 319d34f..9cfd99f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -122,9 +122,9 @@ AS_IF([$PKCONFIG --exists zlib], [
 
 dnl Library target...
 AC_ARG_ENABLE([static], AS_HELP_STRING([--disable-static], [do not install static library]))
-AC_ARG_ENABLE([shared], AS_HELP_STRING([--disable-shared], [do not install shared library]))
+AC_ARG_ENABLE([shared], AS_HELP_STRING([--enable-shared], [install shared library]))
 
-AS_IF([test x$enable_shared != xno], [
+AS_IF([test x$enable_shared = xyes], [
     AS_IF([test "$host_os_name" = darwin], [
 	LIBPDFIO="libpdfio.1.dylib"
     ], [