diff --git a/src/sage/databases/cremona.py b/src/sage/databases/cremona.py
index 0a5f794..2969d92 100644
--- a/src/sage/databases/cremona.py
+++ b/src/sage/databases/cremona.py
@@ -53,7 +53,6 @@ from sage.misc.prandom import randint
 
 import sage.schemes.elliptic_curves.constructor as elliptic
 from .sql_db import SQLDatabase, verify_column
-from sage.misc.package import is_package_installed
 from sage.env import SAGE_SHARE
 from sage.misc.all import walltime
 
@@ -824,7 +823,7 @@ class MiniCremonaDatabase(SQLDatabase):
             if N < self.largest_conductor():
                 message = "There is no elliptic curve with label " + label \
                     + " in the database"
-            elif is_package_installed('database_cremona_ellcurve'):
+            elif os.path.isfile(os.path.join(SAGE_SHARE, "cremona", "cremona.db")):
                 message = "There is no elliptic curve with label " + label \
                     + " in the currently available databases"
             else:
@@ -1673,7 +1672,7 @@ def CremonaDatabase(name=None,mini=None,set_global=None):
     if name is None and not set_global:
         return _db
     if set_global and name is None:
-        if is_package_installed('database_cremona_ellcurve'):
+        if os.path.isfile(os.path.join(SAGE_SHARE, "cremona", "cremona.db")):
             name = 'cremona'
         else:
             name = 'cremona mini'
diff --git a/src/sage/game_theory/normal_form_game.py b/src/sage/game_theory/normal_form_game.py
index b917d2a..80fb20c 100644
--- a/src/sage/game_theory/normal_form_game.py
+++ b/src/sage/game_theory/normal_form_game.py
@@ -614,8 +614,9 @@ from sage.rings.all import QQ
 from sage.structure.sage_object import SageObject
 from sage.matrix.constructor import matrix
 from sage.matrix.constructor import vector
-from sage.misc.package import is_package_installed
 from sage.misc.temporary_file import tmp_filename
+import os
+from sage.env import SAGE_LOCAL
 
 try:
     from gambit import Game
@@ -1317,13 +1318,13 @@ class NormalFormGame(SageObject, MutableMapping):
             raise ValueError("utilities have not been populated")
 
         if not algorithm:
-            if is_package_installed('lrslib'):
+            if os.path.isfile(os.path.join(SAGE_LOCAL, 'bin', 'lrs')):
                 algorithm = "lrs"
             else:
                 algorithm = "enumeration"
 
         if algorithm == "lrs":
-            if not is_package_installed('lrslib'):
+            if not os.path.isfile(os.path.join(SAGE_LOCAL, 'bin', 'lrs')):
                 raise NotImplementedError("lrslib is not installed")
 
             return self._solve_lrs(maximization)
diff --git a/src/sage/geometry/polyhedron/base.py b/src/sage/geometry/polyhedron/base.py
index 2f58d8b..eb519a2 100644
--- a/src/sage/geometry/polyhedron/base.py
+++ b/src/sage/geometry/polyhedron/base.py
@@ -21,7 +21,6 @@ import six
 from sage.structure.element import Element, coerce_binop, is_Vector
 
 from sage.misc.all import cached_method, prod
-from sage.misc.package import is_package_installed
 
 from sage.rings.all import QQ, ZZ
 from sage.rings.real_double import RDF
@@ -3691,7 +3690,9 @@ class Polyhedron_base(Element):
 
              David Avis's lrs program.
         """
-        if not is_package_installed('lrslib'):
+        import os
+        from sage.env import SAGE_LOCAL
+        if os.path.isfile(os.path.join(SAGE_LOCAL, 'bin', 'lrs')) != True:
             raise NotImplementedError('You must install the optional lrslib package '
                                        'for this function to work')
 
diff --git a/src/sage/graphs/generators/classical_geometries.py b/src/sage/graphs/generators/classical_geometries.py
index e80f2a5..04cd9ce 100644
--- a/src/sage/graphs/generators/classical_geometries.py
+++ b/src/sage/graphs/generators/classical_geometries.py
@@ -1287,10 +1287,9 @@ def CossidentePenttilaGraph(q):
         raise ValueError('q(={}) must be an odd prime power'.format(q))
 
     from sage.libs.gap.libgap import libgap
-    from sage.misc.package import is_package_installed, PackageNotFoundError
+    from sage.interfaces.gap import gap
 
-    if not is_package_installed('gap_packages'):
-        raise PackageNotFoundError('gap_packages')
+    gap.load_package("grape")
 
     adj_list=libgap.function_factory("""function(q)
         local z, e, so, G, nu, G1, G0, B, T, s, O1, O2, x;
diff --git a/src/sage/graphs/generic_graph.py b/src/sage/graphs/generic_graph.py
index 252984f..ce19682 100644
--- a/src/sage/graphs/generic_graph.py
+++ b/src/sage/graphs/generic_graph.py
@@ -7858,7 +7858,6 @@ class GenericGraph(GenericGraph_pyx):
            sage: abs(flow_ff-flow_igraph) < 0.00001         # optional python_igraph
            True
         """
-        from sage.misc.package import is_package_installed
         self._scream_if_not_simple(allow_loops=True)
         if vertex_bound and algorithm in ["FF", "igraph"]:
             raise ValueError("This method does not support both " +
@@ -7876,10 +7875,12 @@ class GenericGraph(GenericGraph_pyx):
         if algorithm is None:
             if vertex_bound:
                 algorithm = "LP"
-            elif is_package_installed("python_igraph"):
-                algorithm = "igraph"
             else:
-                algorithm = "FF"
+                algorithm = "igraph"
+                try:
+                    import igraph
+                except ImportError:
+                    algorithm = "FF"
 
         if (algorithm == "FF"):
             return self._ford_fulkerson(x,y, value_only=value_only, integer=integer, use_edge_labels=use_edge_labels)
diff --git a/src/sage/graphs/graph_generators.py b/src/sage/graphs/graph_generators.py
index 5919ab3..1766796 100644
--- a/src/sage/graphs/graph_generators.py
+++ b/src/sage/graphs/graph_generators.py
@@ -1195,8 +1195,9 @@ class GraphGenerators():
         .. [buckygen] \G. Brinkmann, J. Goedgebeur and B.D. McKay, Generation of Fullerenes,
           Journal of Chemical Information and Modeling, 52(11):2910-2918, 2012.
         """
-        from sage.misc.package import is_package_installed
-        if not is_package_installed("buckygen"):
+        import os
+        from sage.env import SAGE_LOCAL
+        if not os.path.isfile(os.path.join(SAGE_LOCAL, 'bin', 'buckygen')):
             raise TypeError("the optional buckygen package is not installed")
 
         # number of vertices should be positive
@@ -1280,8 +1281,9 @@ class GraphGenerators():
         .. [benzene] \G. Brinkmann, G. Caporossi and P. Hansen, A Constructive Enumeration of Fusenes and Benzenoids,
           Journal of Algorithms, 45:155-166, 2002.
         """
-        from sage.misc.package import is_package_installed
-        if not is_package_installed("benzene"):
+        import os
+        from sage.env import SAGE_LOCAL
+        if not os.path.isfile(os.path.join(SAGE_LOCAL, 'bin', 'benzene')):
             raise TypeError("the optional benzene package is not installed")
 
         # number of hexagons should be positive
@@ -1433,8 +1435,9 @@ class GraphGenerators():
         .. [plantri] \G. Brinkmann and B.D. McKay, Fast generation of planar graphs,
            MATCH-Communications in Mathematical and in Computer Chemistry, 58(2):323-357, 2007.
         """
-        from sage.misc.package import is_package_installed
-        if not is_package_installed("plantri"):
+        import os
+        from sage.env import SAGE_LOCAL
+        if not os.path.isfile(os.path.join(SAGE_LOCAL, 'bin', 'plantri')):
             raise TypeError("the optional plantri package is not installed")
 
         # number of vertices should be positive
@@ -1632,8 +1635,9 @@ class GraphGenerators():
             sage: [g.size() for g in graphs.triangulations(6, minimum_connectivity=3)] # optional plantri
             [12, 12]
         """
-        from sage.misc.package import is_package_installed
-        if not is_package_installed("plantri"):
+        import os
+        from sage.env import SAGE_LOCAL
+        if not os.path.isfile(os.path.join(SAGE_LOCAL, 'bin', 'plantri')):
             raise TypeError("the optional plantri package is not installed")
 
         # number of vertices should be positive
@@ -1786,8 +1790,9 @@ class GraphGenerators():
             sage: [len(g) for g in graphs.quadrangulations(12, no_nonfacial_quadrangles=True, dual=True)]  # optional plantri
             [10, 10]
         """
-        from sage.misc.package import is_package_installed
-        if not is_package_installed("plantri"):
+        import os
+        from sage.env import SAGE_LOCAL
+        if not os.path.isfile(os.path.join(SAGE_LOCAL, 'bin', 'plantri')):
             raise TypeError("the optional plantri package is not installed")
 
         # number of vertices should be positive
diff --git a/src/sage/graphs/lovasz_theta.py b/src/sage/graphs/lovasz_theta.py
index 0d345c9..60948d2 100644
--- a/src/sage/graphs/lovasz_theta.py
+++ b/src/sage/graphs/lovasz_theta.py
@@ -65,10 +65,9 @@ def lovasz_theta(graph):
     from sage.misc.temporary_file import tmp_filename
     import os, subprocess
     from sage.env import SAGE_LOCAL
-    from sage.misc.package import is_package_installed, PackageNotFoundError
 
-    if not is_package_installed('csdp'):
-        raise PackageNotFoundError("csdp")
+    if not os.path.isfile(os.path.join(SAGE_LOCAL, 'bin', 'theta')):
+        raise NotImplementedError("You must install csdp before using this function")
 
     g = graph.relabel(inplace=False, perm=range(1,n+1)).networkx_graph()
     tf_name = tmp_filename()
diff --git a/src/sage/groups/generic.py b/src/sage/groups/generic.py
index c801636..f43e6d9 100644
--- a/src/sage/groups/generic.py
+++ b/src/sage/groups/generic.py
@@ -1400,15 +1400,15 @@ def structure_description(G, latex=False):
         sage: groups.matrix.GL(4,2).structure_description() # optional - database_gap
         'A8'
     """
-    import re
-    from sage.misc.package import is_package_installed
+    import re, os
+    from sage.env import SAGE_LOCAL
     def correct_dihedral_degree(match):
         return "%sD%d" % (match.group(1), int(match.group(2))/2)
 
     try:
         description = str(G._gap_().StructureDescription())
     except RuntimeError:
-        if not is_package_installed('database_gap'):
+	if not os.path.isfile(os.path.join(SAGE_LOCAL, "lib", "gap", "small", "readsml.g")):
             raise RuntimeError("You must install the optional database_gap package first.")
         raise
 
diff --git a/src/sage/groups/perm_gps/permgroup.py b/src/sage/groups/perm_gps/permgroup.py
index e42db61..d4d5684 100644
--- a/src/sage/groups/perm_gps/permgroup.py
+++ b/src/sage/groups/perm_gps/permgroup.py
@@ -145,7 +145,6 @@ from sage.groups.perm_gps.permgroup_element import PermutationGroupElement, stan
 from sage.groups.abelian_gps.abelian_group import AbelianGroup
 from sage.misc.cachefunc import cached_method
 from sage.groups.class_function import ClassFunction
-from sage.misc.package import is_package_installed
 from sage.sets.finite_enumerated_set import FiniteEnumeratedSet
 from sage.categories.all import FiniteEnumeratedSets
 from sage.groups.conjugacy_classes import ConjugacyClassGAP
@@ -190,8 +189,6 @@ def hap_decorator(f):
     """
     @wraps(f)
     def wrapped(self, n, p=0):
-        if not is_package_installed('gap_packages'):
-            raise RuntimeError("You must install the optional gap_packages package.")
         load_hap()
         from sage.arith.all import is_prime
         if not (p == 0 or is_prime(p)):
@@ -1682,9 +1679,7 @@ class PermutationGroup_generic(group.FiniteGroup):
         try:
             return [Integer(n) for n in self._gap_().IdGroup()]
         except RuntimeError:
-            if not is_package_installed('database_gap'):
-                raise RuntimeError("You must install the optional database_gap package first.")
-            raise
+            raise RuntimeError("You must install the optional gap_packages package.")
 
     def id(self):
         """
@@ -1735,9 +1730,7 @@ class PermutationGroup_generic(group.FiniteGroup):
         try:
             return Integer(self._gap_().PrimitiveIdentification())
         except RuntimeError:
-            if not is_package_installed('database_gap'):
-                raise RuntimeError("You must install the optional database_gap package first.")
-            raise
+            raise RuntimeError("You must install the optional gap_packages package.")
 
     def center(self):
         """
@@ -4113,8 +4106,6 @@ class PermutationGroup_generic(group.FiniteGroup):
         - David Joyner and Graham Ellis
 
         """
-        if not is_package_installed('gap_packages'):
-            raise RuntimeError("You must install the optional gap_packages package.")
         load_hap()
         from sage.arith.all import is_prime
         if not (p == 0 or is_prime(p)):
diff --git a/src/sage/misc/all.py b/src/sage/misc/all.py
index 90e6985..21daeb0 100644
--- a/src/sage/misc/all.py
+++ b/src/sage/misc/all.py
@@ -53,11 +53,6 @@ from fpickle import pickle_function, unpickle_function
 
 from .dist import install_scripts
 
-from .package import (install_package,
-        installed_packages, is_package_installed,
-        standard_packages, optional_packages, experimental_packages,
-        upgrade, package_versions)
-
 from .pager import pager
 
 lazy_import('sage.misc.sagedoc', ['browse_sage_doc',
diff --git a/src/sage/rings/polynomial/multi_polynomial_sequence.py b/src/sage/rings/polynomial/multi_polynomial_sequence.py
index da41cb0..49cae0b 100644
--- a/src/sage/rings/polynomial/multi_polynomial_sequence.py
+++ b/src/sage/rings/polynomial/multi_polynomial_sequence.py
@@ -163,7 +163,6 @@ from sage.misc.cachefunc import cached_method
 
 from types import GeneratorType
 from sage.misc.converting_dict import KeyConvertingDict
-from sage.misc.package import is_package_installed
 
 from sage.structure.sequence import Sequence, Sequence_generic
 
@@ -1433,10 +1432,11 @@ class PolynomialSequence_gf2(PolynomialSequence_generic):
 
         if S != []:
             if algorithm == "exhaustive_search":
-                if not is_package_installed('fes'):
-                    from sage.misc.package import PackageNotFoundError
-                    raise PackageNotFoundError("fes")
-                from sage.libs.fes import exhaustive_search
+                try:
+                    from sage.libs.fes import exhaustive_search
+                except ImportError:
+                    raise RuntimeError("You must install the optional fes package.")
+
                 solutions = exhaustive_search(S, max_sols=n, verbose=verbose, **kwds)
 
             elif algorithm == "polybori":