diff -ur a/configure.ac b/configure.ac
--- a/configure.ac	2020-02-15 12:44:55.065569980 +0100
+++ b/configure.ac	2020-02-15 14:08:21.905767776 +0100
@@ -9,7 +9,9 @@
 AC_PROG_CC
 AC_PROG_INSTALL
 AC_PROG_CXX
-AC_PROG_RANLIB
+LT_INIT
+AC_ENABLE_SHARED
+AC_DISABLE_STATIC
 
 dnl Checks for libraries.
 dnl Replace `main' with a function in -lg:
@@ -18,10 +20,6 @@
 dnl AC_CHECK_LIB(stdc, main)
 dnl Replace `main' with a function in -lstdc++:
 dnl AC_CHECK_LIB(stdc++, main)
-dnl Make libgmp:
-make -C external gmp
-dnl Make libcddgmp:
-make -C external cdd
 dnl Check for soplex:
 AC_CHECK_LIB(soplex, main, , csh -c 'echo soplex not found: --soplex will not work.')
 
diff -ur a/lib-src/Makefile.am b/lib-src/Makefile.am
--- a/lib-src/Makefile.am	2020-02-15 12:44:55.145570436 +0100
+++ b/lib-src/Makefile.am	2020-02-15 14:08:44.741903592 +0100
@@ -1,6 +1,6 @@
-lib_LIBRARIES       = libTOPCOM.a
+lib_LTLIBRARIES       = libTOPCOM.la
 
-libTOPCOM_a_SOURCES = \
+libTOPCOM_la_SOURCES = \
 Admissibles.cc \
 CheckTriang.cc \
 Circuits.cc \
@@ -90,9 +90,9 @@
 
 AM_CPPFLAGS     = -I../lib-src-reg
 AM_CPPFLAGS    += -I../wrap-gmp-gmpxx
-AM_CPPFLAGS    += -I../external/include
+AM_CPPFLAGS    += $(CPPFLAGS)
 AM_CPPFLAGS    += -I$(includedir)
 
 AM_CPPFLAGS    += -DVERBOSE -DGMPRATIONAL -ftemplate-depth-35
 
-AM_CXXFLAGS     = -O2 -g
+AM_CXXFLAGS     = $(CXXFLAGS)
diff -ur a/lib-src-reg/Makefile.am b/lib-src-reg/Makefile.am
--- a/lib-src-reg/Makefile.am	2020-02-15 12:44:55.165570550 +0100
+++ b/lib-src-reg/Makefile.am	2020-02-15 14:08:22.921773817 +0100
@@ -1,6 +1,6 @@
-lib_LIBRARIES = libCHECKREG.a
+lib_LTLIBRARIES = libCHECKREG.la
 
-libCHECKREG_a_SOURCES = \
+libCHECKREG_la_SOURCES = \
 SPXinterface.cc \
 LPinterface.cc \
 RegularityCheck.cc
@@ -12,9 +12,9 @@
 
 AM_CPPFLAGS     = -I../lib-src 
 AM_CPPFLAGS    += -I../wrap-gmp-gmpxx
-AM_CPPFLAGS    += -I../external/include
+AM_CPPFLAGS    += $(CPPFLAGS)
 AM_CPPFLAGS    += -I$(includedir)
 
 AM_CPPFLAGS    += -DVERBOSE -DGMPRATIONAL -ftemplate-depth-30
 
-AM_CXXFLAGS     = -O2
+AM_CXXFLAGS     = $(CXXFLAGS)
diff -ur a/Makefile.am b/Makefile.am
--- a/Makefile.am	2020-02-15 12:44:55.065569980 +0100
+++ b/Makefile.am	2020-02-15 14:08:22.929773865 +0100
@@ -1,6 +1 @@
 SUBDIRS      = wrap-gmp-gmpxx lib-src-reg lib-src src-reg src examples
-EXTRA_DIST   = external/Makefile
-EXTRA_DIST  += external/gmp-6.1.1.tar.bz2
-EXTRA_DIST  += external/cddlib-0.94f-TOPCOM.tar.gz
-EXTRA_DIST  += external/gmpxx-patch
-
diff -ur a/src/Makefile.am b/src/Makefile.am
--- a/src/Makefile.am	2020-02-15 12:44:55.165570550 +0100
+++ b/src/Makefile.am	2020-02-15 14:08:22.933773888 +0100
@@ -83,18 +83,14 @@
 santos_dim4_triang_SOURCES         = santos_dim4_triang.cc
 santos_22_triang_SOURCES           = santos_22_triang.cc
 
-LDADD           = ../lib-src/libTOPCOM.a \
-                  ../lib-src-reg/libCHECKREG.a \
-                  ../external/lib/libcddgmp.a \
-                  ../external/lib/libgmpxx.a \
-                  ../external/lib/libgmp.a
-
 AM_CPPFLAGS     = -I../lib-src
 AM_CPPFLAGS    += -I../lib-src-reg
+AM_CPPFLAGS    += -L../lib-src-reg
+AM_CPPFLAGS    += -L../lib-src
 AM_CPPFLAGS    += -I../wrap-gmp-gmpxx
-AM_CPPFLAGS    += -I../external/include
+AM_CPPFLAGS    += $(CPPFLAGS)
 AM_CPPFLAGS    += -I$(includedir)
 
-AM_CPPFLAGS    += -DVERBOSE -DGMPRATIONAL -ftemplate-depth-30
+AM_CPPFLAGS    += -DVERBOSE -DGMPRATIONAL -ftemplate-depth-30 -lTOPCOM -lCHECKREG
 
-AM_CXXFLAGS     = -O2
+AM_CXXFLAGS     = $(CXXFLAGS) -L../lib-src-reg -L../lib-src -lTOPCOM -lCHECKREG
diff -ur a/src-reg/Makefile.am b/src-reg/Makefile.am
--- a/src-reg/Makefile.am	2020-02-15 12:44:55.165570550 +0100
+++ b/src-reg/Makefile.am	2020-02-15 14:08:22.933773888 +0100
@@ -2,20 +2,15 @@
 
 checkregularity_SOURCES = checkregularity.cc
 
-LDADD           = ../lib-src-reg/libCHECKREG.a \
-                  ../lib-src/libTOPCOM.a \
-                  ../external/lib/libcddgmp.a \
-                  ../external/lib/libgmpxx.a \
-                  ../external/lib/libgmp.a
-
 AM_CPPFLAGS     = -I../lib-src
 AM_CPPFLAGS    += -I../lib-src-reg
+AM_CPPFLAGS    += -L../lib-src-reg
+AM_CPPFLAGS    += -L../lib-src
 AM_CPPFLAGS    += -I../wrap-gmp-gmpxx
-AM_CPPFLAGS    += -I../external/include
+AM_CPPFLAGS    += $(CPPFLAGS)
 AM_CPPFLAGS    += -I$(includedir)
 
 
-AM_CPPFLAGS    += -DVERBOSE -DGMPRATIONAL -ftemplate-depth-30
-
-AM_CXXFLAGS     = -O2
+AM_CPPFLAGS    += -DVERBOSE -DGMPRATIONAL -ftemplate-depth-30 -lTOPCOM -lCHECKREG
 
+AM_CXXFLAGS     = $(CXXFLAGS) -L../lib-src-reg -L../lib-src -lTOPCOM -lCHECKREG
diff -ur a/wrap-gmp-gmpxx/Makefile.am b/wrap-gmp-gmpxx/Makefile.am
--- a/wrap-gmp-gmpxx/Makefile.am	2020-02-15 12:44:55.165570550 +0100
+++ b/wrap-gmp-gmpxx/Makefile.am	2020-02-15 14:08:23.105774912 +0100
@@ -3,6 +3,6 @@
 Rational.h
 
 AM_CPPFLAGS        = -I../external/include
-AM_CPPFLAGS       += -I$(includedir)
+AM_CPPFLAGS       += -I$(includedir) $(CPPFLAGS)
 
-AM_CXXFLAGS     = -O2
+AM_CXXFLAGS     = $(CXXFLAGS)