diff --git a/Makefile b/Makefile
index f7943be..67fbc33 100644
--- a/Makefile
+++ b/Makefile
@@ -38,7 +38,7 @@ snow:
 	snow-chibi install --impls=generic --skip-tests?=1 --always-yes --install-source-dir=snow --install-library-dir=snow srfi.64 || true
 
 ${VENV}:
-	scheme-venv ${SCHEME} ${RNRS} ${VENV}
+	scheme-venv ${SCHEME} ${VENV}
 	if [ "${RNRS}" = "r7rs" ]; then ${VENV}/bin/snow-chibi install --always-yes srfi.64; fi
 	if [ "${RNRS}" = "r7rs" ]; then ${VENV}/bin/snow-chibi install --always-yes retropikzel.mouth; fi
 	if [ "${RNRS}" = "r7rs" ]; then ${VENV}/bin/snow-chibi install --always-yes retropikzel.ctrf; fi
diff --git a/retropikzel/memoize.scm b/retropikzel/memoize.scm
new file mode 100644
index 0000000..4593fb0
--- /dev/null
+++ b/retropikzel/memoize.scm
@@ -0,0 +1,2 @@
+(define (memoize thunk)
+  (force (delay (apply thunk '()))))
diff --git a/retropikzel/memoize.sld b/retropikzel/memoize.sld
new file mode 100644
index 0000000..0356ad1
--- /dev/null
+++ b/retropikzel/memoize.sld
@@ -0,0 +1,6 @@
+(define-library
+  (retropikzel memoize)
+  (import (scheme base)
+          (scheme lazy))
+  (export memoize)
+  (include "memoize.scm"))
diff --git a/retropikzel/memoize/LICENSE b/retropikzel/memoize/LICENSE
new file mode 100644
index 0000000..0a04128
--- /dev/null
+++ b/retropikzel/memoize/LICENSE
@@ -0,0 +1,165 @@
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
+
+  "The Library" refers to a covered work governed by this License,
+other than an Application or a Combined Work as defined below.
+
+  An "Application" is any work that makes use of an interface provided
+by the Library, but which is not otherwise based on the Library.
+Defining a subclass of a class defined by the Library is deemed a mode
+of using an interface provided by the Library.
+
+  A "Combined Work" is a work produced by combining or linking an
+Application with the Library.  The particular version of the Library
+with which the Combined Work was made is also called the "Linked
+Version".
+
+  The "Minimal Corresponding Source" for a Combined Work means the
+Corresponding Source for the Combined Work, excluding any source code
+for portions of the Combined Work that, considered in isolation, are
+based on the Application, and not on the Linked Version.
+
+  The "Corresponding Application Code" for a Combined Work means the
+object code and/or source code for the Application, including any data
+and utility programs needed for reproducing the Combined Work from the
+Application, but excluding the System Libraries of the Combined Work.
+
+  1. Exception to Section 3 of the GNU GPL.
+
+  You may convey a covered work under sections 3 and 4 of this License
+without being bound by section 3 of the GNU GPL.
+
+  2. Conveying Modified Versions.
+
+  If you modify a copy of the Library, and, in your modifications, a
+facility refers to a function or data to be supplied by an Application
+that uses the facility (other than as an argument passed when the
+facility is invoked), then you may convey a copy of the modified
+version:
+
+   a) under this License, provided that you make a good faith effort to
+   ensure that, in the event an Application does not supply the
+   function or data, the facility still operates, and performs
+   whatever part of its purpose remains meaningful, or
+
+   b) under the GNU GPL, with none of the additional permissions of
+   this License applicable to that copy.
+
+  3. Object Code Incorporating Material from Library Header Files.
+
+  The object code form of an Application may incorporate material from
+a header file that is part of the Library.  You may convey such object
+code under terms of your choice, provided that, if the incorporated
+material is not limited to numerical parameters, data structure
+layouts and accessors, or small macros, inline functions and templates
+(ten or fewer lines in length), you do both of the following:
+
+   a) Give prominent notice with each copy of the object code that the
+   Library is used in it and that the Library and its use are
+   covered by this License.
+
+   b) Accompany the object code with a copy of the GNU GPL and this license
+   document.
+
+  4. Combined Works.
+
+  You may convey a Combined Work under terms of your choice that,
+taken together, effectively do not restrict modification of the
+portions of the Library contained in the Combined Work and reverse
+engineering for debugging such modifications, if you also do each of
+the following:
+
+   a) Give prominent notice with each copy of the Combined Work that
+   the Library is used in it and that the Library and its use are
+   covered by this License.
+
+   b) Accompany the Combined Work with a copy of the GNU GPL and this license
+   document.
+
+   c) For a Combined Work that displays copyright notices during
+   execution, include the copyright notice for the Library among
+   these notices, as well as a reference directing the user to the
+   copies of the GNU GPL and this license document.
+
+   d) Do one of the following:
+
+       0) Convey the Minimal Corresponding Source under the terms of this
+       License, and the Corresponding Application Code in a form
+       suitable for, and under terms that permit, the user to
+       recombine or relink the Application with a modified version of
+       the Linked Version to produce a modified Combined Work, in the
+       manner specified by section 6 of the GNU GPL for conveying
+       Corresponding Source.
+
+       1) Use a suitable shared library mechanism for linking with the
+       Library.  A suitable mechanism is one that (a) uses at run time
+       a copy of the Library already present on the user's computer
+       system, and (b) will operate properly with a modified version
+       of the Library that is interface-compatible with the Linked
+       Version.
+
+   e) Provide Installation Information, but only if you would otherwise
+   be required to provide such information under section 6 of the
+   GNU GPL, and only to the extent that such information is
+   necessary to install and execute a modified version of the
+   Combined Work produced by recombining or relinking the
+   Application with a modified version of the Linked Version. (If
+   you use option 4d0, the Installation Information must accompany
+   the Minimal Corresponding Source and Corresponding Application
+   Code. If you use option 4d1, you must provide the Installation
+   Information in the manner specified by section 6 of the GNU GPL
+   for conveying Corresponding Source.)
+
+  5. Combined Libraries.
+
+  You may place library facilities that are a work based on the
+Library side by side in a single library together with other library
+facilities that are not Applications and are not covered by this
+License, and convey such a combined library under terms of your
+choice, if you do both of the following:
+
+   a) Accompany the combined library with a copy of the same work based
+   on the Library, uncombined with any other library facilities,
+   conveyed under the terms of this License.
+
+   b) Give prominent notice with the combined library that part of it
+   is a work based on the Library, and explaining where to find the
+   accompanying uncombined form of the same work.
+
+  6. Revised Versions of the GNU Lesser General Public License.
+
+  The Free Software Foundation may publish revised and/or new versions
+of the GNU Lesser General Public License from time to time. Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.
+
+  Each version is given a distinguishing version number. If the
+Library as you received it specifies that a certain numbered version
+of the GNU Lesser General Public License "or any later version"
+applies to it, you have the option of following the terms and
+conditions either of that published version or of any later version
+published by the Free Software Foundation. If the Library as you
+received it does not specify a version number of the GNU Lesser
+General Public License, you may choose any version of the GNU Lesser
+General Public License ever published by the Free Software Foundation.
+
+  If the Library as you received it specifies that a proxy can decide
+whether future versions of the GNU Lesser General Public License shall
+apply, that proxy's public statement of acceptance of any version is
+permanent authorization for you to choose that version for the
+Library.
diff --git a/retropikzel/memoize/README.md b/retropikzel/memoize/README.md
new file mode 100644
index 0000000..e69de29
diff --git a/retropikzel/memoize/VERSION b/retropikzel/memoize/VERSION
new file mode 100644
index 0000000..3eefcb9
--- /dev/null
+++ b/retropikzel/memoize/VERSION
@@ -0,0 +1 @@
+1.0.0
diff --git a/retropikzel/memoize/test.scm b/retropikzel/memoize/test.scm
new file mode 100644
index 0000000..1f91c5f
--- /dev/null
+++ b/retropikzel/memoize/test.scm
@@ -0,0 +1,14 @@
+(test-begin "memoize")
+
+(define x 1)
+
+(define (two) (memoize (lambda () (+ 1 x))))
+(write (two))
+(newline)
+
+(set! x 2)
+(write (two))
+(newline)
+
+(test-end "memoize")
+
diff --git a/retropikzel/record.scm b/retropikzel/record.scm
new file mode 100644
index 0000000..a5a659b
--- /dev/null
+++ b/retropikzel/record.scm
@@ -0,0 +1,32 @@
+(define-syntax record
+  (syntax-rules ()
+    ((_ (field value) ...)
+     (let ((field value) ...)
+       (lambda (name . val)
+         (cond ((equal? 'field name)
+                (if (null? val)
+                  field
+                  (set! field (car val)))) ...))))))
+
+(define-syntax immutable-record
+  (syntax-rules ()
+    ((_ (field value) ...)
+     (lambda (name)
+       (cond ((equal? 'field name) value) ...)))))
+
+(define-syntax typed-record
+  (syntax-rules ()
+    ((_ (field value type-check) ...)
+     (let ((field value) ...)
+       (lambda (name . val)
+         (cond ((equal? 'field name)
+                (if (null? val)
+                  field
+                  (if (type-check (car val))
+                    (set! field (car val))
+                    (error (string-append "type-check fail "
+                                          (symbol->string name))
+                           `((,name ,(car val))
+                             (type-check ,type-check)))
+                           )))
+               ...))))))
diff --git a/retropikzel/record.sld b/retropikzel/record.sld
new file mode 100644
index 0000000..8947839
--- /dev/null
+++ b/retropikzel/record.sld
@@ -0,0 +1,7 @@
+(define-library
+  (retropikzel record)
+  (import (scheme base))
+  (export record
+          immutable-record
+          typed-record)
+  (include "record.scm"))
diff --git a/retropikzel/record/LICENSE b/retropikzel/record/LICENSE
new file mode 100644
index 0000000..0a04128
--- /dev/null
+++ b/retropikzel/record/LICENSE
@@ -0,0 +1,165 @@
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
+
+  "The Library" refers to a covered work governed by this License,
+other than an Application or a Combined Work as defined below.
+
+  An "Application" is any work that makes use of an interface provided
+by the Library, but which is not otherwise based on the Library.
+Defining a subclass of a class defined by the Library is deemed a mode
+of using an interface provided by the Library.
+
+  A "Combined Work" is a work produced by combining or linking an
+Application with the Library.  The particular version of the Library
+with which the Combined Work was made is also called the "Linked
+Version".
+
+  The "Minimal Corresponding Source" for a Combined Work means the
+Corresponding Source for the Combined Work, excluding any source code
+for portions of the Combined Work that, considered in isolation, are
+based on the Application, and not on the Linked Version.
+
+  The "Corresponding Application Code" for a Combined Work means the
+object code and/or source code for the Application, including any data
+and utility programs needed for reproducing the Combined Work from the
+Application, but excluding the System Libraries of the Combined Work.
+
+  1. Exception to Section 3 of the GNU GPL.
+
+  You may convey a covered work under sections 3 and 4 of this License
+without being bound by section 3 of the GNU GPL.
+
+  2. Conveying Modified Versions.
+
+  If you modify a copy of the Library, and, in your modifications, a
+facility refers to a function or data to be supplied by an Application
+that uses the facility (other than as an argument passed when the
+facility is invoked), then you may convey a copy of the modified
+version:
+
+   a) under this License, provided that you make a good faith effort to
+   ensure that, in the event an Application does not supply the
+   function or data, the facility still operates, and performs
+   whatever part of its purpose remains meaningful, or
+
+   b) under the GNU GPL, with none of the additional permissions of
+   this License applicable to that copy.
+
+  3. Object Code Incorporating Material from Library Header Files.
+
+  The object code form of an Application may incorporate material from
+a header file that is part of the Library.  You may convey such object
+code under terms of your choice, provided that, if the incorporated
+material is not limited to numerical parameters, data structure
+layouts and accessors, or small macros, inline functions and templates
+(ten or fewer lines in length), you do both of the following:
+
+   a) Give prominent notice with each copy of the object code that the
+   Library is used in it and that the Library and its use are
+   covered by this License.
+
+   b) Accompany the object code with a copy of the GNU GPL and this license
+   document.
+
+  4. Combined Works.
+
+  You may convey a Combined Work under terms of your choice that,
+taken together, effectively do not restrict modification of the
+portions of the Library contained in the Combined Work and reverse
+engineering for debugging such modifications, if you also do each of
+the following:
+
+   a) Give prominent notice with each copy of the Combined Work that
+   the Library is used in it and that the Library and its use are
+   covered by this License.
+
+   b) Accompany the Combined Work with a copy of the GNU GPL and this license
+   document.
+
+   c) For a Combined Work that displays copyright notices during
+   execution, include the copyright notice for the Library among
+   these notices, as well as a reference directing the user to the
+   copies of the GNU GPL and this license document.
+
+   d) Do one of the following:
+
+       0) Convey the Minimal Corresponding Source under the terms of this
+       License, and the Corresponding Application Code in a form
+       suitable for, and under terms that permit, the user to
+       recombine or relink the Application with a modified version of
+       the Linked Version to produce a modified Combined Work, in the
+       manner specified by section 6 of the GNU GPL for conveying
+       Corresponding Source.
+
+       1) Use a suitable shared library mechanism for linking with the
+       Library.  A suitable mechanism is one that (a) uses at run time
+       a copy of the Library already present on the user's computer
+       system, and (b) will operate properly with a modified version
+       of the Library that is interface-compatible with the Linked
+       Version.
+
+   e) Provide Installation Information, but only if you would otherwise
+   be required to provide such information under section 6 of the
+   GNU GPL, and only to the extent that such information is
+   necessary to install and execute a modified version of the
+   Combined Work produced by recombining or relinking the
+   Application with a modified version of the Linked Version. (If
+   you use option 4d0, the Installation Information must accompany
+   the Minimal Corresponding Source and Corresponding Application
+   Code. If you use option 4d1, you must provide the Installation
+   Information in the manner specified by section 6 of the GNU GPL
+   for conveying Corresponding Source.)
+
+  5. Combined Libraries.
+
+  You may place library facilities that are a work based on the
+Library side by side in a single library together with other library
+facilities that are not Applications and are not covered by this
+License, and convey such a combined library under terms of your
+choice, if you do both of the following:
+
+   a) Accompany the combined library with a copy of the same work based
+   on the Library, uncombined with any other library facilities,
+   conveyed under the terms of this License.
+
+   b) Give prominent notice with the combined library that part of it
+   is a work based on the Library, and explaining where to find the
+   accompanying uncombined form of the same work.
+
+  6. Revised Versions of the GNU Lesser General Public License.
+
+  The Free Software Foundation may publish revised and/or new versions
+of the GNU Lesser General Public License from time to time. Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.
+
+  Each version is given a distinguishing version number. If the
+Library as you received it specifies that a certain numbered version
+of the GNU Lesser General Public License "or any later version"
+applies to it, you have the option of following the terms and
+conditions either of that published version or of any later version
+published by the Free Software Foundation. If the Library as you
+received it does not specify a version number of the GNU Lesser
+General Public License, you may choose any version of the GNU Lesser
+General Public License ever published by the Free Software Foundation.
+
+  If the Library as you received it specifies that a proxy can decide
+whether future versions of the GNU Lesser General Public License shall
+apply, that proxy's public statement of acceptance of any version is
+permanent authorization for you to choose that version for the
+Library.
diff --git a/retropikzel/record/README.md b/retropikzel/record/README.md
new file mode 100644
index 0000000..e69de29
diff --git a/retropikzel/record/VERSION b/retropikzel/record/VERSION
new file mode 100644
index 0000000..6e8bf73
--- /dev/null
+++ b/retropikzel/record/VERSION
@@ -0,0 +1 @@
+0.1.0
diff --git a/retropikzel/record/test.scm b/retropikzel/record/test.scm
new file mode 100644
index 0000000..494dc2d
--- /dev/null
+++ b/retropikzel/record/test.scm
@@ -0,0 +1,31 @@
+(test-begin "record")
+
+
+(define player (record (x 10) (y 10) (health 10)))
+
+(write player)
+(newline)
+(write (player 'x))
+(newline)
+(player 'x 100)
+(write (player 'x))
+(newline)
+
+(define tree (immutable-record (x 10) (y 10)))
+
+(write tree)
+(newline)
+(write (tree 'x))
+(newline)
+
+(define dog (typed-record (x 10 (lambda (x) (and (> x 10) (integer? x)))) (y 10 integer?)))
+
+(write dog)
+(newline)
+(write (dog 'x))
+(newline)
+(dog 'x 3)
+(write (dog 'x))
+(newline)
+
+(test-end "record")