##### user-visible changes:

- SymPy is now 2x faster in average compared to the previous release (see below)
`integrate()`can handle most of the basic integrals now (commit)- interactive experience with isympy was improved through adding support for [], () and {} to pretty-printer, and switching to it as the default ipython printer (commit 1, 2, 3)
- new
`trim()`function to map all non-atomic expressions, ie. functions, derivatives and more complex objects, to symbols and remove common factors from numerator and denominator. also`cancel()`was improved (commit 1, 2) `.expand()`for noncommutative symbols fixed (commit)- bug in
`(x+y+sin(x)).as_independent()`fixed (commit) `.subs_dict()`improved (commit)- support for plotting geometry objects added (commit)
- bug in
`.tangent_line()`of ellipse fixed (commit 1, 2) - new
`atan2`function and assotiated fixes for`.arg()`and expanding rational powers (commit 1, 2, 3) - new
`.coeff()`method for returning coefficient of a poly (commit 1, 2, 3) - pretty-printer now uses unicode by default (commit)
- recognition of geometric sums were generalized (commit)
`.is_positive`and`.is_negative`now fallback to evalf() when appropriate (commit)- as the result
`oo*(pi-1)`now correctly simplifies to`oo`(commit) - support for objects which provide
`__int__`method was added (commit) - we finally started SymPy User's Guide (commit 1, 2)

##### changes that affected speed:

- first patches with 25% speedup (commit 1, 2, 3, 4)
- Basic.cos et. al. removed, use C.cos instead (commit 1, 2, 3, 4)
- sympy.core now uses direct imports (commit 1, 2)
- sympifyit decorator (commit 1, 2, 3, 4, 5, 6, 7)
- speedup Integers creation and arithmetic (commit 1, 2)
- speedup unary operations for singleton numbers (commit)
- remove silly slowdowns from fast-path of mul and div (commit 1, 2)
- significant speedup was achieved by reusing dummy variables (commit 1, 2, 3, 4)
`is_dummy`is not an assumption anymore (commit 1, 2)- Symbols & Wilds are cached (commit 1, 2, 3)
`((2+3*I)**1000).expand()`is now at least 100x faster (commit)`.expand()`was made faster for cases where an expression is already expanded (commit)- rational powers of integers are now computed more efficiently (commit)
- unknown assumptions are now cached as well as known assumptions (commit)

##### general cleanup:

- BasicMeths merged into Basic (commit 1, 2, 3, 4, 5, 6, 7, 8)
- cache subsystem was cleaned up -- now it supports only immutable objects (commit 1, 2, 3, 4, 5)

The following people have contributed to this release:

- Kirill Smelkov
- Mateusz Paprocki
- Saroj Adhikari
- Fredrik Johansson
- Jaroslaw Tworek
- Robert Kern
- Pauli Virtanen
- Ondřej Čertík