diff --git a/curriculum.json b/curriculum.json
index e3b4274..1700e12 100644
--- a/curriculum.json
+++ b/curriculum.json
@@ -10,14 +10,9 @@
             ],
             "Courses":[
                 {"Name":"Python for Everyone",
-                "URL":"https://www.coursera.org/specializations/python",
-                "Alternative":"https://www.py4e.com/",
+                "URL":"https://www.py4e.com/",
                 "Effort":"58 hours",
-                "Prerequisites":"none"},
-                {"Name":"Fundamentals of Computing",
-                "URL":"https://www.coursera.org/specializations/computer-fundamentals",
-                "Effort":"138 hours",
-                "Prerequisites":"high school mathematics"}
+                "Prerequisites":"none"}
              ]},
             {"Name":"Introduction to CS Tools",
             "Explanation":"Understanding theory is important, but you will also be expected to create programs. There are a number of tools that are widely used to make that process easier. Learn them now to ease your future work writing programs.",
@@ -110,7 +105,7 @@
                      "URL":"https://www.edx.org/course/calculus-1a-differentiation",
                      "Duration":"13 weeks",
                      "Effort":"6-10 hours/week",
-                     "Prerequisites":"[pre-calculus](https://www.futurelearn.com/courses/precalculus)"},
+                     "Prerequisites":"high school math"},
                      {"Name":"Calculus 1B: Integration",
                      "URL":"https://www.edx.org/course/calculus-1b-integration",
                      "Duration":"13 weeks",
@@ -128,10 +123,9 @@
                      "URL":"https://www.youtube.com/playlist?list=PLZHQObOWTQDPD3MizzM2xVFitgF8hE_ab",
                      "Duration":" - ",
                      "Effort":" - ",
-                     "Prerequisites":"[pre-calculus](https://www.futurelearn.com/courses/precalculus)"},
+                     "Prerequisites":"high school math"},
                      {"Name":"Linear Algebra",
                      "URL":"https://ocw.mit.edu/courses/mathematics/18-06sc-linear-algebra-fall-2011/",
-                     "Alternative":"http://ulaff.net/",
                      "Duration":"14 weeks",
                      "Effort":"12 hours/week",
                      "Prerequisites":"Essence of Linear Algebra"}
@@ -146,9 +140,9 @@
                      ]},
                  {"Name":"Probability",
                  "Courses":[
-                     {"Name":"Introduction to Probability - The Science of Uncertainty",
-                     "URL":"https://www.edx.org/course/introduction-probability-science-mitx-6-041x-2",
-                     "Duration":"18 weeks",
+                     {"Name":"Probability",
+                     "URL":"https://projects.iq.harvard.edu/stat110/home",
+                     "Duration":"24 weeks",
                      "Effort":"12 hours/week",
                      "Prerequisites":"[Multivariable Calculus](https://ocw.mit.edu/courses/mathematics/18-02sc-multivariable-calculus-fall-2010/index.htm)"}
                      ]}
@@ -215,7 +209,7 @@
                 "Additional Text / Assignments":"[Assignment 1](https://github.com/PrincetonUniversity/COS461-Public/tree/master/assignments/assignment1)<br>[Assignment 2](https://www.scs.stanford.edu/10au-cs144/lab/reliable/reliable.html)<br>[Assignment 3](https://nptel.ac.in/content/storage2/courses/106105080/pdf/M2L7.pdf)<br>[Assignment 4](http://www-net.cs.umass.edu/wireshark-labs/Wireshark_TCP_v7.0.pdf)",
                 "Prerequisites":"algebra, probability, basic CS"},
                 {"Name":"Operating Systems: Three Easy Pieces",
-                "URL":"http://pages.cs.wisc.edu/~remzi/OSTEP/",
+                "URL":"http://pages.cs.wisc.edu/~remzi/Classes/537/Spring2018/",
                 "Duration":"10-12 weeks",
                 "Effort":"6 hours/week",
                 "Additional Text / Assignments":"[Homework](http://pages.cs.wisc.edu/~remzi/OSTEP/Homework/homework.html) [Lectures](https://www.youtube.com/channel/UCGweYi6vcfHaTrkap3c1TPg/videos) [Supplement](http://pages.cs.wisc.edu/~shivaram/cs537-sp20/",
@@ -352,12 +346,11 @@
             {"Name":"and more"}
         ],
         "Courses":[
-            {"Name":"Introduction to Parallel Programming",
-            "URL":"https://classroom.udacity.com/courses/cs344",
-            "Alternative":"https://www.youtube.com/playlist?list=PLGvfHSgImk4aweyWlhBXNF6XISY3um82",
-            "Duration":"12 weeks",
-            "Effort":" - ",
-            "Prerequisites":"C, algorithms"},
+            {"Name":"Parallel Programming",
+            "URL":"https://www.coursera.org/learn/parprog1",
+            "Duration":"4 weeks",
+            "Effort":" 6-8 hours/week ",
+            "Prerequisites":"Scala Programming"},
             {"Name":"Compilers",
             "URL":"https://www.edx.org/course/compilers",
             "Alternative":"https://www.youtube.com/playlist?list=PLDcmCgguL9rxPoVn2ykUFc8TOpLyDU5gx",
@@ -382,11 +375,6 @@
             "Duration":"4 weeks",
             "Effort":"6 hours/week",
             "Prerequisites":"Python, programming experience"},
-            {"Name":"LAFF - On Programming for Correctness",
-            "URL":"https://www.edx.org/course/laff-on-programming-for-correctness",
-            "Duration":"7 weeks",
-            "Effort":"6 hours/week",
-            "Prerequisites":"linear algebra"},
             {"Name":"Software Architecture & Design",
             "URL":"https://www.udacity.com/course/software-architecture-design--ud821",
             "Duration":"8 weeks",
@@ -412,21 +400,11 @@
             {"Name":"and more"}
         ],
         "Courses":[
-            {"Name":"Electricity and Magnetism, Part 1",
-            "URL":"https://www.edx.org/course/electricity-magnetism-part-1-ricex-phys102-1x-0",
-            "Duration":"7 weeks",
-            "Effort":"8-10 hours/week",
-            "Prerequisites":"[calculus](https://www.khanacademy.org/math/calculus-1), [basic mechanics](https://www.khanacademy.org/science/physics)"},
-            {"Name":"Electricity and Magnetism, Part 2",
-            "URL":"https://www.edx.org/course/electricity-magnetism-part-2-ricex-phys102-2x-0",
-            "Duration":"7 weeks",
-            "Effort":"8-10 hours/week",
-            "Prerequisites":"Electricity and Magnetism, Part 1"},
             {"Name":"Computation Structures 1: Digital Circuits",
             "URL":"https://www.edx.org/course/computation-structures-part-1-digital-mitx-6-004-1x-0",
             "Duration":"10 weeks",
             "Effort":"6 hours/week",
-            "Prerequisites":"electricity, magnetism"},
+            "Prerequisites":"Nand2Tetris II"},
             {"Name":"Computation Structures 2: Computer Architecture",
             "URL":"https://www.edx.org/course/computation-structures-2-computer-mitx-6-004-2x",
             "Duration":"10 weeks",
@@ -510,10 +488,10 @@
             "Duration":"30 weeks",
             "Effort":"2-6 hours/week",
             "Prerequisites":"C++ programming"},
-            {"Name":"Full Stack Web Development (Specialization)",
-            "URL":"https://www.coursera.org/specializations/full-stack",
-            "Duration":"27 weeks",
-            "Effort":"2-6 hours/week",
+            {"Name":"Fullstack Open",
+            "URL":"https://fullstackopen.com/en",
+            "Duration":"12 weeks",
+            "Effort":"6 hours/week",
             "Prerequisites":"programming, databases"},
             {"Name":"Data Science (Specialization)",
             "URL":"https://www.coursera.org/specializations/jhu-data-science",