diff --git a/GNUmakefile b/GNUmakefile
index 6af3ae74..ba7196ef 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -11,8 +11,17 @@ default: all
 all:
 	./build.sh
 
+cc:
+	build-aux/build-cc.sh
+
+mlibc:
+	build-aux/build-mlibc.sh
+
+mes:
+	build-aux/build-mes.sh
+
 clean:
-	true
+	git clean -dfx
 
 all-go:
 	build-aux/build-guile.sh
@@ -30,12 +39,31 @@ install:
 .config.make: ./configure
 
 seed:
-	cd ../mes-seed && git reset --hard HEAD
-	MES=guile GUILE=guile SEED=1 build-aux/build-mes.sh
-	cd ../mes-seed && ./refresh.sh && cd ../mes
-	MES=guile GUILE=guile SEED=1 build-aux/build-mes.sh
+	cd $(MES_SEED) && git reset --hard HEAD
+	MES=$(GUILE) GUILE=$(GUILE) SEED=1 build-aux/build-mes.sh
+	cd $(MES_SEED) && MES_PREFIX=$(PWD) ./refresh.sh
+	MES=$(GUILE) GUILE=$(GUILE) SEED=1 build-aux/build-mes.sh
 	build-aux/build-mlibc.sh
-	cd ../tinycc-seed && ./refresh.sh && cd ../mes
+	cd $(TINYCC_SEED) && MES_PREFIX=$(PWD) ./refresh.sh
+
+define HELP_TOP
+Usage: make [OPTION]... [TARGET]...
+
+Targets:
+  all             update everything
+  all-go          update .go files
+  cc              update src/mes.gcc-out
+  mlibc           update src/mes.mlibc-out
+  mes             update src/mes
+  check           run unit tests
+  clean           run git clean -dfx
+  clean-go        clean .go files
+  install         install in $(PREFIX)
+  seed            update mes-seed in $(MES_SEED)
+endef
+export HELP_TOP
+help:
+	@echo "$$HELP_TOP"
 
 ifdef PREFIX
 export PREFIX
@@ -53,6 +81,10 @@ ifdef CC32
 export CC32
 endif
 
+ifdef BLOOD_ELF
+export BLOOD_ELF
+endif
+
 ifdef M1
 export M1
 endif
@@ -65,6 +97,10 @@ ifdef GUILE
 export GUILE
 endif
 
+ifdef GUILE_TOOLS
+export GUILE_TOOLS
+endif
+
 ifdef GUILE_LOAD_PATH
 export GUILE_LOAD_PATH
 endif
@@ -93,4 +129,10 @@ ifdef MESCCFLAGS
 export MESCCFLAGS
 endif
 
+ifdef MES_SEED
+export MES_SEED
+endif
 
+ifdef TINYCC_SEED
+export TINYCC_SEED
+endif
diff --git a/configure b/configure
index 7ecc29a0..81b18a63 100755
--- a/configure
+++ b/configure
@@ -24,7 +24,7 @@ Missing dependencies, run
 EOF
     exit 1
 fi
-exec ${GUILE-guile} --no-auto-compile -e '(configure)' -s "$0" ${1+"$@"}
+exec ${GUILE-guile} -L . --no-auto-compile -e '(configure)' -s "$0" ${1+"$@"}
 !#
 
 ;;; Mes --- Maxwell Equations of Software
@@ -220,6 +220,10 @@ Some influential environment variables:
   CFLAGS      C compiler flags
   CC32        x86 C compiler command
   C32FLAGS    x86 C compiler flags
+  GUILE       guile command
+  GUILE_TOOLS guile-tools command
+  MES_SEED    location of mes-seed
+  TINYCC_SEED location of tinycc-seed
 " PACKAGE VERSION (getenv "PREFIX")))
 
 (define (main args)
@@ -240,20 +244,28 @@ Some influential environment variables:
     (let ((CC32 (or (getenv "CC32")
                     (if (member ARCH '("i686" "arm")) (string-append BUILD_TRIPLET "-" CC)
                         "i686-unknown-linux-gnu-gcc")))
+          (GUILE_TOOLS (or (getenv "GUILE_TOOLS") "guile-tools"))
+          (BLOOD_ELF (or (getenv "BLOOD_ELF") "blood-elf"))
           (HEX2 (or (getenv "HEX2") "hex2"))
           (M1 (or (getenv "M1") "M1"))
           (CFLAGS (getenv "CFLAGS"))
           (C32FLAGS (getenv "C32FLAGS"))
           (HEX2FLAGS (getenv "HEX2FLAGS"))
           (M1FLAGS (getenv "M1FLAGS"))
-          (MESCCFLAGS (getenv "MESCCFLAGS")))
+          (MESCCFLAGS (getenv "MESCCFLAGS"))
+          (MES_SEED (or (getenv "MES_SEED") "../mes-seed"))
+          (TINYCC_SEED (or (getenv "TINYCC_SEED") "../tinycc-seed")))
       (when help?
         (print-help)
         (exit 0))
       (set! *verbose?* verbose?)
       (check-version "guile" '(2 0))
-      (check-version HEX2 '(0 1))
-      (check-version M1 '(0 2))
+      (check-version "guile-tools" '(2 0))
+      (check-version "mes-seed" '(0 14) #:optional? #t #:command (string-append MES_SEED "/refresh.sh"))
+      (check-version "tinycc-seed" '(0 14) #:optional? #t #:command (string-append TINYCC_SEED "/refresh.sh"))
+      (check-version BLOOD_ELF '(0 1))
+      (check-version HEX2 '(0 3))
+      (check-version M1 '(0 3))
       (check-version "nyacc" '(0 80 41) #:command (string-append GUILE " -c '(use-modules (nyacc lalr)) (display *nyacc-version*)'"))
 
       (check-version "bash" '(4 0))
@@ -284,9 +296,13 @@ Some influential environment variables:
           (stdout "ARCH:=~a\n" ARCH)
           (stdout "CC:=~a\n" (or CC ""))
           (stdout "CC32:=~a\n" (or CC32 ""))
+          (stdout "BLOOD_ELF:=~a\n" (or BLOOD_ELF ""))
+          (stdout "MES_SEED:=~a\n" (or MES_SEED ""))
+          (stdout "TINYCC_SEED:=~a\n" (or TINYCC_SEED ""))
           (stdout "HEX2:=~a\n" (or HEX2 ""))
           (stdout "M1:=~a\n" (or M1 ""))
           (stdout "GUILE:=~a\n" GUILE)
+          (stdout "GUILE_TOOLS:=~a\n" GUILE_TOOLS)
           (stdout "GUILE_FOR_BUILD:=~a\n" GUILE)
           (stdout "GUILE_EFFECTIVE_VERSION:=~a\n" GUILE_EFFECTIVE_VERSION)
           (stdout "GUIX_P:=~a\n" (if guix? guix? ""))