.NET 10 adds custom unhandled exception handlers! Better control over catastrophic failures. Hook into exception handling without app domain events.

.NET 10 adds AES Key Wrap with Padding (RFC 5649)! Before: RFC 3394 required key length to be multiple of 64 bits. Now: wrap any size key! Essential for modern key management.

.NET 10 adds experimental AsyncHelpers for blocking on async code (when you must)! ⚠️ Use sparingly - only when you truly can't use async/await. Better than .Result or .Wait() though!

.NET 10 adds Clear() and Text to DefaultInterpolatedStringHandler! Build interpolated strings incrementally. Zero allocations when using the span!

.NET 10 adds NumericOrdering to CompareOptions - natural sort! Sorts "file2" before "file10" like humans expect!

.NET 10 adds GetOrAdd overloads to ConditionalWeakTable! Thread-safe, atomic. Just like ConcurrentDictionary!

.NET 10 adds NamedWaitHandleOptions for better cross-process synchronization! Better security isolation for named synchronization primitives. Prevents cross-user/session conflicts.

.NET 10 extends ISOWeek (which holds a special place in my 🥰) to work with DateOnly! No more DateOnly→DateTime conversions. Direct ISO week calculations.

.NET 10 provides InlineArray2 through InlineArray16 helpers! Stack-allocated fixed-size arrays for any type. Great for high-performance scenarios without heap allocations.

.NET 10 adds BigMul for 128-bit integers - get both high and low parts! No overflow - capture the full result of massive multiplications!