Freeware Limitations:
no commercial use is allowed
lacks all features introduced in IDA > v5.0: v5.1, v5.2, v5.3, v5.4, v5.5, v5.6, v5.7, v6.0, v6.1, v6.2, v6.3, v6.4, v6.5, v6.6 v6.7 v6.8
lacks support for many processors, file formats, debugging etc...
comes without technical support...