diff --git a/VERSION.txt b/VERSION.txt
index 6a6098389d1..8cffa2607a9 100644
--- a/VERSION.txt
+++ b/VERSION.txt
@@ -1 +1 @@
-Sage version 6.5, released 2015-02-17
+Sage version 6.6.beta0, released 2015-02-18
diff --git a/build/pkgs/configure/checksums.ini b/build/pkgs/configure/checksums.ini
index 0c7f2dd8408..dd0594bcee2 100644
--- a/build/pkgs/configure/checksums.ini
+++ b/build/pkgs/configure/checksums.ini
@@ -1,4 +1,4 @@
 tarball=configure-VERSION.tar.gz
-sha1=aeb5074139b3b14da2ca9a462fa5c437d4b9ad7f
-md5=2e95587b653681877f7665264bb364c1
-cksum=244132514
+sha1=fc6a6e09db9e9ef7877296947cfcc0929b6d08bf
+md5=ca43ab046439d42063bf4af39baecb18
+cksum=3453818239
diff --git a/build/pkgs/configure/package-version.txt b/build/pkgs/configure/package-version.txt
index b5489e5e51a..2bbd69c2e54 100644
--- a/build/pkgs/configure/package-version.txt
+++ b/build/pkgs/configure/package-version.txt
@@ -1 +1 @@
-69
+70
diff --git a/src/bin/sage-banner b/src/bin/sage-banner
index ae9e688f3c7..5f46b3af2fd 100644
--- a/src/bin/sage-banner
+++ b/src/bin/sage-banner
@@ -1,5 +1,8 @@
 ┌────────────────────────────────────────────────────────────────────┐
-│ Sage Version 6.5, Release Date: 2015-02-17                         │
+│ Sage Version 6.6.beta0, Release Date: 2015-02-18                   │
 │ Type "notebook()" for the browser-based notebook interface.        │
 │ Type "help()" for help.                                            │
 └────────────────────────────────────────────────────────────────────┘
+┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
+┃ Warning: this is a prerelease version, and it may be unstable.     ┃
+┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
diff --git a/src/bin/sage-version.sh b/src/bin/sage-version.sh
index 2b6402fde1e..ff9bbcbce2a 100644
--- a/src/bin/sage-version.sh
+++ b/src/bin/sage-version.sh
@@ -1,4 +1,4 @@
 # Sage version information for shell scripts
 # This file is auto-generated by the sage-update-version script, do not edit!
-SAGE_VERSION='6.5'
-SAGE_RELEASE_DATE='2015-02-17'
+SAGE_VERSION='6.6.beta0'
+SAGE_RELEASE_DATE='2015-02-18'
diff --git a/src/sage/version.py b/src/sage/version.py
index a2e6916aef9..6af99d7ad07 100644
--- a/src/sage/version.py
+++ b/src/sage/version.py
@@ -1,4 +1,4 @@
 # Sage version information for Python scripts
 # This file is auto-generated by the sage-update-version script, do not edit!
-version = '6.5'
-date = '2015-02-17'
+version = '6.6.beta0'
+date = '2015-02-18'