CFR will decompile modern Java features - Java 8 lambdas (pre and post Java beta 103 changes), Java 7 String switches etc, but is written entirely in Java 6. [ http://www.benf.org/other/cfr/ ].

Comments about CFR as an Alternative to ILSpy

CFR is the most popular Mac & Linux alternative to ILSpy.
- CFR is Free and Open Source
They are both decompilers, but ILSpy is for Microsoft MSIL used in C#/F#/VB &c., while CFR is for JVM ByteCodes, using in Java and a pile of other JVM languages ... so while they have the same theoretical "function", they don't overlap at all in actual use!