https://medium.com/@ingonyama/icicle-v3-1c9cc2f94402

ICICLE v3 is a cryptography library focused on accelerating ZKPs. Here are the major highlights:

• Multi-Platform Support: ICICLE now supports both CPUs and GPUs, allowing users to easily switch between hardware for increased flexibility.
• Enhanced Performance: Optimizations in GPU usage lead to faster execution times, and larger primitives like MSM and NTT can now be handled more efficiently.
• Extended Vector Operations: New vector-scalar operations (e.g., addition, subtraction, multiplication) have been added.
• Merkle Tree Enhancements: ICICLE now allows for the use of different hash functions within a single tree, with upcoming support for Blake2s/c and Keccak.
• CPU Support: Emphasis on extracting more performance from commodity CPUs, with future plans for ARM and Google TPUs.

Purpose:

• ICICLE: ICICLE is a cryptography library designed to accelerate ZKPs by providing low-level tools, especially for polynomial operations, across multiple hardware platforms (CPUs, GPUs, etc.). It focuses on speeding up the core mathematical components of ZKPs, making it a building block for cryptographic protocols.
• zk-VM: A zk-VM is a virtual machine that supports the execution of programs with privacy and integrity using Zero-Knowledge Proofs. It allows developers to write and run applications (smart contracts, ZK rollups, etc.) where the correctness of the computation is verifiable without revealing the underlying data.

Abstraction Level:

• ICICLE: Operates at a lower level, providing cryptographers with tools to implement ZKP primitives (like MSM, NTT, and hash functions) more efficiently. ICICLE is a library, so it needs to be integrated into a larger ZKP system or cryptographic protocol.
• zk-VM: Provides a higher level of abstraction, allowing developers to write and run entire applications on top of the zk-VM. It provides a full execution environment where the correctness of any program’s execution can be proven using ZKPs.

Use Case:

• ICICLE: Primarily used by cryptographers and protocol developers who need to accelerate the computation of specific cryptographic operations. It's ideal for building custom ZK applications or enhancing the performance of existing ZKP frameworks.
• zk-VM: Geared toward developers who want to create decentralized applications (dApps), layer-2 solutions, or privacy-preserving systems without needing deep expertise in cryptographic primitives. zk-VMs can be used to prove the execution of entire programs.

Flexibility:

• ICICLE: It’s more flexible in the sense that it can be used to build a variety of ZKP-related protocols from the ground up. ICICLE allows for granular control over polynomial operations and hardware resource allocation, which is useful for optimizing ZKP-heavy systems.
• zk-VM: Provides a more structured, less flexible environment because it focuses on executing predefined programs or smart contracts within a VM framework. While you can build applications, you don't have as much low-level control over the cryptographic processes.