diff --git a/build.pl b/build.pl
new file mode 100755
index 000000000..305e30ea2
--- /dev/null
+++ b/build.pl
@@ -0,0 +1,205 @@
+#!/usr/bin/perl
+
+use strict;
+use Getopt::Long;
+
+my $opt_list;
+my $opt_eachclean;
+my $opt_verbose;
+
+GetOptions("list" => \$opt_list,
+           "eachclean" => \$opt_eachclean,
+           "verbose" => \$opt_verbose,
+    ) or usage();
+
+sub usage {
+    die <<EOM
+Usage:
+  build.pl all         # build all
+  build.pl clean       # clean all
+  build.pl REGEXP      # builds specific target, if it matches any targets
+  build.pl --list
+  build.pl --eachclean # builds each target with a full clean before it
+                       # (for testing that dependencies are correct)
+
+Other options:
+  --verbose|-v         Verbose
+EOM
+;
+}
+
+my %built;  # target -> bool (was it already built?)
+my %targets;  # dir -> { deps => [ ... ], } 
+read_targets();
+
+if ($opt_list)  {
+    print "Available targets:\n";
+    foreach my $target (sort keys %targets) {
+        print "  * $target\n";
+    }
+    exit;        
+}
+
+if ($opt_eachclean) {
+    my $target = shift;
+    die "--eachclean doesn't take a target\n" if $target;
+    foreach my $target (sort keys %targets) {
+        clean();
+        %built = ();
+        build($target);
+    }
+    exit;
+}
+
+my $target = shift or usage();
+
+if ($target eq "clean") {
+    clean();
+    exit;
+}
+
+if ($target eq "all") {
+    foreach my $target (sort keys %targets) {
+        build($target);
+    }
+    exit;
+}
+
+my @matches = grep { /$target/ } sort keys %targets;
+unless (@matches) {
+    die "No build targets patching pattern /$target/\n";
+}
+if (@matches > 1) {
+    die "Build pattern is ambiguous, matches multiple targets:\n  * " . join("\n  * ", @matches) . "\n";
+}
+
+build($matches[0]);
+
+sub v {
+    return unless $opt_verbose;
+    my $msg = shift;
+    chomp $msg;
+    print STDERR "# $msg\n";
+}
+
+sub clean {
+    for my $root ("$ENV{GOROOT}/pkg/linux_amd64",
+                 "$ENV{GOROOT}/pkg/linux_386") {
+        for my $pkg ("camli", "crypto/openpgp") {
+            my $dir = "$root/$pkg";
+            next unless -d $dir;
+            system("rm", "-rfv", $dir);
+        }
+    }
+    foreach my $target (sort keys %targets) {
+        print STDERR "Cleaning $target\n";
+        system("make", "-C", $target, "clean");
+    }
+}
+
+sub build {
+    my @history = @_;
+    my $target = $history[0];
+    my $already_built = $built{$target} || 0;
+    v("Building '$target' (already_built=$already_built; via @history)");
+    return if $already_built;
+    $built{$target} = 1;
+
+    my $t = $targets{$target} or die "Bogus build target: $target\n";
+
+    # Dependencies first.
+    my @deps = @{ $t->{deps} };
+    if (@deps) {
+        v("Deps of '$target' are @deps");
+        foreach my $dep (@deps) {
+            build($dep, @history);
+        }
+        v("built deps for $target, now can build");
+    }
+
+    my @quiet = ("--silent");
+    @quiet = () if $opt_verbose;
+
+    if (system("make", @quiet, "-C", $target, "install") != 0) {
+        my $chain = "";
+        if (@history > 1) {
+            $chain = "(via chain @history)";
+        }
+        die "Error building $target $chain\n";
+    }
+    v("Built '$target'");
+}
+
+sub read_targets {
+    my $last;
+    for (<DATA>) {
+        if (m!^\./(.+)/Makefile\s*$!) {
+            my $target = $1;
+            $last = $target;
+            $targets{$target} ||= { deps => [] };
+            next;
+        }
+        if (m!^\s+\-\s(\S+)\s*$!) {
+            my $dep = $1;
+            my $t = $targets{$last} or die "Unexpected dependency line: $_";
+            push @{$t->{deps}}, $dep;
+        }
+    }
+    #use Data::Dumper;
+    #print Dumper(\%targets);
+}
+
+__DATA__
+./server/go/httputil/Makefile
+    # (no deps)
+./server/go/auth/Makefile
+    # (no deps)
+./server/go/webserver/Makefile
+    # (no deps)
+./server/go/blobserver/Makefile
+    - server/go/httputil
+    - lib/go/blobref
+    - server/go/auth
+    - server/go/webserver
+./server/go/sigserver/Makefile
+    - server/go/webserver
+    - lib/go/blobref
+    - server/go/auth
+    - server/go/httputil
+    - lib/go/jsonsign
+    - lib/go/ext/openpgp/packet
+    - lib/go/ext/openpgp/error
+    - lib/go/ext/openpgp/armor
+./website/Makefile
+    # (no deps, yet)
+./clients/go/camput/Makefile
+    - lib/go/client
+    - lib/go/blobref
+    - lib/go/schema
+./clients/go/camget/Makefile
+    - lib/go/client
+    - lib/go/blobref
+    - lib/go/schema
+./lib/go/http/Makefile
+    # (no deps, fork of Go's http library)
+./lib/go/ext/openpgp/error/Makefile
+    # (no deps)
+./lib/go/ext/openpgp/packet/Makefile
+    - lib/go/ext/openpgp/error
+./lib/go/ext/openpgp/armor/Makefile
+    - lib/go/ext/openpgp/error
+    - lib/go/ext/openpgp/packet
+./lib/go/schema/Makefile
+    - lib/go/blobref
+./lib/go/client/Makefile
+    - lib/go/http
+    - lib/go/blobref
+./lib/go/jsonsign/Makefile
+    - lib/go/blobref
+    - lib/go/ext/openpgp/packet
+    - lib/go/ext/openpgp/armor
+    - lib/go/ext/openpgp/error
+./lib/go/blobref/Makefile
+    # (on deps)
+
+
diff --git a/dev-camget b/dev-camget
index 8f471bc4c..339998556 100755
--- a/dev-camget
+++ b/dev-camget
@@ -1,6 +1,4 @@
 #!/bin/sh
 
-make -C lib/go/schema/ install && \
-  make -C lib/go/client install && \
-  make -C clients/go/camget/ && \
+./build.pl camget && \
   clients/go/camget/camget --verbose --blobserver=localhost:3179 --password=foo $@
diff --git a/dev-camput b/dev-camput
index 05e31184c..3ab027271 100755
--- a/dev-camput
+++ b/dev-camput
@@ -1,6 +1,4 @@
 #!/bin/sh
 
-make -C lib/go/schema/ install && \
-  make -C lib/go/client install && \ 
-  make -C clients/go/camput/ && \
+./build.pl camput && \
   clients/go/camput/camput --verbose --blobserver=localhost:3179 --password=foo --file $@