Criticism

Performance

The garbage-collector, which is chip into the environment, can acquaint hasty delays of beheading over which the developer has little absolute control, and it can could cause runtime anamnesis admeasurement to be beyond than expected. "In ample applications, the amount of altar that the debris beneficiary needs to accord with can become actual large, which agency it can yield a actual continued time to appointment and adapt all of them." 20

The .NET Framework currently does not accommodate abutment for calling Streaming SIMD Extensions (SSE) via managed code. However, Mono has provided abutment for SIMD Extensions as of adaptation 2.2 aural the Mono.Simd namespace; Mono's advance developer Miguel de Icaza has bidding achievement that this SIMD abutment will be adopted by the CLR ECMA standard.21 Streaming SIMD Extensions accept been accessible in x86 CPUs back the addition of the Pentium III. Some added architectures such as ARM and MIPS aswell accept SIMD extensions. In case the CPU lacks abutment for those extensions, the instructions are apish in software.

editSecurity

Unobfuscated managed CIL bytecode can generally be easier to reverse-engineer than built-in code.2223 One affair is over accessible accident of barter secrets and the bypassing of authorization ascendancy mechanisms. To abate this, Microsoft included the Dotfuscator Community Edition obfuscation apparatus aural Visual Studio .NET back 2002.24 Third-party obfuscation solutions are aswell accessible from vendors such as vmware, V.i. Labs, Xenocode, Red Gate Software and others.

.NET Decompiler programs such as .NET Reflector accredit developers with no reverse-engineering abilities to appearance the antecedent cipher abaft unobfuscated .NET assemblies (DLL/EXE). In contrast, applications congenital with Visual C++ are abundant harder to reverse-engineer and antecedent cipher is about never produced successfully, even with decompiling programs such as IDA Pro.

editAvailability

While the standards that accomplish up .NET are inherently cross-platform, Microsoft's abounding accomplishing of .NET is accurate alone on Windows.

Newer versions of the framework (3.5 and up) are not pre-installed in versions of Windows beneath Windows 7 (although newer versions are accessible via Windows Update). For this reason, applications accept to advance users after the framework through a action to install it. Some developers accept bidding apropos about the ample admeasurement of the .NET Framework runtime installers for end-users. The admeasurement is about 54 MB for .NET 3.0, 197 MB for .NET 3.5, and 250 MB for .NET 3.5 SP1 (while application web installer the archetypal download for Windows XP is about 50 MB — for Windows Vista, 20 MB). The admeasurement affair is partially apparent with .NET 4 installer (x86 + x64) getting 54 MB and not embedding abounding runtime accession bales for antecedent versions. The .NET 3.5 SP1 abounding accession amalgamation includes the abounding runtime accession bales for .NET 2.0 SP2 as able-bodied as .NET 3.0 SP2 for assorted operating systems (Windows XP/Server 2003 and Windows Vista/Server 2008) and for assorted CPU architectures (x86, x86-64, and IA-64).

The aboriginal account backpack for adaptation 3.5 mitigates this affair by alms a lighter-weight client-only subset of the .NET Framework. Two cogent limitations should be noted, though.25 Firstly, the client-only subset is alone an advantage on an absolute Windows XP SP2 arrangement that currently has no added adaptation of the .NET Framework installed. In all added scenarios, the client-only installer will install the abounding adaptation of the .NET Framework 3.5 SP1. Secondly, the client-only framework does not accept a 64-bit option. However, the 4 absolution of the .NET Framework Client Profile will be accessible on all operating systems and all architectures (excluding Itanium) accurate by the abounding .NET Framework.26