Since the changes are huge and it is easy to lose your way, we prepared a Porting guide from the IDA 4.9-6.x API to the IDA 7.0 API which explains what has changed and how. Function names and their functionality are the same in most cases, but we tried to stay pythonic in Python and C++-ish in the C++ interface. We also tried to make our 3 APIs: C++, Python, and IDC, to be closer to each other. We minutely tested all changes and ensured that all our tests continue to pass as before or better. The fundamental concepts remain the same and IDA did not lose any bit of its functionality during the cleanup. If we failed or succeeded is to be seen, but we ourselves like the new API much more. Second, we took this change as an opportunity (since old 32-bit plugins won't work with 64-bit IDA anyway) to clean up the IDA API, make it more consistent and less confusing. For example, IDAPython integration will be easier and more streamlined because many operating systems nowadays come with the 64-bit Python preinstalled (32-bit Python won't work anymore). The biggest news is that IDA is a native 64-bit application! First of all it means that now it can eat all memory of your computer and thrash it But jokes aside, switching to 64-bit aligns IDA with other modern software and makes it more compatible with the rest of the world. Hex-Rays SA has released 14 (September 14, 2017) version of IDA, is the Interactive DisAssembler: the world's smartest and most feature-full disassembler, which many software security specialists are familiar with. IDA Pro 14 with Hex-Rays Decompilers | 542.7 mb

Hexrays decompiler download